Traditionally, spirituality refers to a religious process of re-formation which "aims to recover the original shape of man," oriented at "the image of God" as exemplified by the founders and sacred texts of the religions of the world. In modern times the emphasis is on subjective experience of a sacred dimension and the "deepest values and meanings by which people live," often in a context separate from organized religious institutions. Modern spirituality typically includes a belief in a supernatural (beyond the known and observable) realm, personal growth , a quest for an ultimate/sacred meaning , religious experience , or an encounter with one's own "inner dimension."
The meaning of spirituality has developed and expanded over time, and various connotations can be found alongside each other. The term "spirituality" originally developed within early Christianity, referring to a life oriented toward the Holy Spirit . During late medieval times the meaning broadened to include mental aspects of life, while in modern times the term both spread to other religious traditions and broadened to refer to a wider range of experience, including a range of esoteric traditions.
The term spirit means "animating or vital principle in man and animals".  It is derived from the Old French espirit  which comes from the Latin word spiritus ( soul , courage, vigor, breath)  and is related to spirare (to breathe).  In the Vulgate the Latin word spiritus is used to translate the Greek pneuma and Hebrew ruah . 
There is no single, widely agreed definition of spirituality. Surveys of the definition of the term, as used in scholarly research, show a broad range of definitions ranging from uni-dimensional definitions such as a personal belief in a supernatural realm to broader concepts such as a quest for an ultimate/sacred meaning, transcending the base/material aspects of life, and/or a sense of awe/wonderment and reverence toward the universe. A survey of reviews by McCarroll e.a. dealing with the topic of spirituality gave twenty-seven explicit definitions, among which "there was little agreement." This causes some difficulty in trying to study spirituality systematically; i.e., it impedes both understanding and the capacity to communicate findings in a meaningful fashion. Indeed, many of spirituality's core features are not unique to spirituality alone; for example German philosopher Arthur Schopenhauer (a famous atheist) regarded self- transcendence , asceticism and the recognition of one's connection to all as a key to ethical living
According to Kees Waaijman, the traditional meaning of spirituality is a process of re-formation which "aims to recover the original shape of man, the image of God. To accomplish this, the re-formation is oriented at a mold, which represents the original shape: in Judaism the Torah , in Christianity there is Christ , for Buddhism , Buddha , and in Islam , Muhammad ." In modern times the emphasis is on subjective experience and the "deepest values and meanings by which people live," incorporating personal growth or transformation , usually in a context separate from organized religious institutions. Houtman and Aupers suggest that modern spirituality is a blend of humanistic psychology, mystical and esoteric traditions and eastern religions.
Spirituality is sometimes associated with philosophical, social, or political movements such as liberalism , feminist theology , and green politics . Some argue (though far from universally accepted—see those who espouse secular humanism )spirituality is intimately linked to resolving mental health issues, managing substance abuse , marital functioning, parenting , and coping .
Development of the meaning of spirituality
Classical, medieval and early modern periods
Words translatable as 'spirituality' first began to arise in the 5th century and only entered common use toward the end of the Middle Ages. In a Biblical context the term means being animated by God, to be driven by the Holy Spirit , as opposed to a life which rejects this influence.
In the 11th century this meaning changed. Spirituality began to denote the mental aspect of life, as opposed to the material and sensual aspects of life, "the ecclesiastical sphere of light against the dark world of matter". In the 13th century "spirituality" acquired a social and psychological meaning. Socially it denoted the territory of the clergy: "The ecclesiastical against the temporary possessions, the ecclesiastical against the secular authority, the clerical class against the secular class" Psychologically, it denoted the realm of the inner life: "The purity of motives, affections, intentions, inner dispositions, the psychology of the spiritual life, the analysis of the feelings".
In the 17th and 18th century a distinction was made between higher and lower forms of spirituality: "A spiritual man is one who is Christian 'more abundantly and deeper than others'." The word was also associated with mysticism and quietism, and acquired a negative meaning.
Modern notions of spirituality developed throughout the 19th and 20th century, mixing Christian ideas with westen esoteric traditions and elements of Asian, especially Indian, religions. Spirituality became increasingly disconnected from traditional religious organisations and institutions.
Transcendentalism and Unitarian Universalism
Ralph Waldo Emerson (1803–1882) was a pioneer of the idea of spirituality as a distinct field. He was one of the major figures in Transcendentalism , an early 19th-century liberal Protestant movement, which was rooted in English and German Romanticism , the Biblical criticism of Johann Gottfried Herder and Friedrich Schleiermacher , the skepticism of Hume ,  and Neo-Platonism . The Transcendentalists emphasised an intuitive, experiential approach of religion.  Following Schleiermacher, an individual's intuition of truth was taken as the criterion for truth.  In the late 18th and early 19th century, the first translations of Hindu texts appeared, which were also read by the Transcendentalists, and influenced their thinking.  They also endorsed universalist and Unitarianist ideas, leading to Unitarian Universalism , the idea that there must be truth in other religions as well, since a loving God would redeem all living beings, not just Christians.  
Theosophy, Anthroposophy, and the Perennial Philosophy
A major influence on modern spirituality was the Theosophical Society , which searched for 'secret teachings' in Asian religions. It has been influential on modernist streams in several Asian religions, notably Neo-Vedanta , the revival of Theravada Buddhism , and Buddhist modernism , which have taken over modern western notions of personal experience and universalism and integrated them in their religious concepts. A second, related influence was Anthroposophy , whose founder, Rudolf Steiner , was particularly interested in developing a genuine Western spirituality, and in the ways that such a spirituality could transform practical institutions such as education , agriculture , and medicine . 
The influence of Asian traditions on western modern spirituality was also furthered by the Perennial Philosophy , whose main proponent Aldous Huxley was deeply influenced by Swami Vivekananda's Neo-Vedanta and Universalism , and the spread of social welfare, education and mass travel after World War Two .
An important influence on western spirituality was Neo-Vedanta , also called neo-Hinduism and Hindu Universalism ,  a modern interpretation of Hinduism which developed in response to western colonialism and orientalism . It aims to present Hinduism as a "homogenized ideal of Hinduism" with Advaita Vedanta as its central doctrine. Due to the colonisation of Asia by the western world, since the 19th century an exchange of ideas has been taking place between the western world and Asia, which also influenced western religiosity. Unitarianism, and the idea of Universalism, was brought to India by missionaries, and had a major influence on neo-Hinduism via Ram Mohan Roy 's Brahmo Samaj and Brahmoism . Roy attempted to modernise and reform Hinduism, from the idea of Universalism. This universalism was further popularised, and brought back to the west as neo-Vedanta, by Swami Vivekananda .
"Spiritual but not religious"
After the Second World War spirituality and religion became disconnected, and spirituality became more oriented on subjective experience, instead of "attempts to place the self within a broader ontological context." A new discourse developed, in which (humanistic) psychology, mystical and esoteric traditions and eastern religions are being blended, to reach the true self by self-disclosure , free expression and meditation.
The distinction between the spiritual and the religious became more common in the popular mind during the late 20th century with the rise of secularism and the advent of the New Age movement. Authors such as Chris Griscom and Shirley MacLaine explored it in numerous ways in their books. Paul Heelas noted the development within New Age circles of what he called "seminar spirituality": structured offerings complementing consumer choice with spiritual options.
Among other factors, declining membership of organized religions and the growth of secularism in the western world have given rise to this broader view of spirituality. Even the secular are finding use for spiritual beliefs. In his books, Michael Mamas makes the case for integrating Eastern spiritual knowledge with Western rational thought.
Rabbinic Judaism (or in some Christian traditions, Rabbinism) (Hebrew: "Yahadut Rabanit" - יהדות רבנית) has been the mainstream form of Judaism since the 6th century CE, after the codification of the Talmud . It is characterised by the belief that the Written Torah ("Law" or "Instruction") cannot be correctly interpreted without reference to the Oral Torah and by the voluminous literature specifying what behavior is sanctioned by the law (called halakha , "the way").
Kabbalah (literally "receiving"), is an esoteric method, discipline and school of thought of Judaism. Its definition varies according to the tradition and aims of those following it, from its religious origin as an integral part of Judaism , to its later Christian , New Age , or Occultist syncretic adaptations. Kabbalah is a set of esoteric teachings meant to explain the relationship between an unchanging, eternal and mysterious Ein Sof (no end) and the mortal and finite universe (his creation). While it is heavily used by some denominations, it is not a religious denomination in itself. Inside Judaism, it forms the foundations of mystical religious interpretation. Outside Judaism, its scriptures are read outside the traditional canons of organised religion. Kabbalah seeks to define the nature of the universe and the human being, the nature and purpose of existence, and various other ontological questions. It also presents methods to aid understanding of these concepts and to thereby attain spiritual realisation.
Hasidic Judaism , meaning "piety" (or " loving kindness "), is a branch of Orthodox Judaism that promotes spirituality through the popularisation and internalisation of Jewish mysticism as the fundamental aspect of the faith. It was founded in 18th-century Eastern Europe by Rabbi Israel Baal Shem Tov as a reaction against overly legalistic Judaism. His example began the characteristic veneration of leadership in Hasidism as embodiments and intercessors of Divinity for the followers. Opposite to this, Hasidic teachings cherished the sincerity and concealed holiness of the unlettered common folk, and their equality with the scholarly elite. The emphasis on the Immanent Divine presence in everything gave new value to prayer and deeds of kindness, alongside Rabbinic supremacy of study , and replaced historical mystical (kabbalistic) and ethical (musar) asceticism and admonishment with optimism, encouragement, and daily fervour . This populist emotional revival accompanied the elite ideal of nullification to paradoxical Divine Panentheism , through intellectual articulation of inner dimensions of mystical thought.
Catholic spirituality is the spiritual practice of living out a personal act of faith ( fides qua creditur ) following the acceptance of faith ( fides quae creditur ). Although all Catholics are expected to pray together at Mass , there are many different forms of spirituality and private prayer which have developed over the centuries. Each of the major religious orders of the Catholic Church and other lay groupings have their own unique spirituality - its own way of approaching God in prayer and in living out the Gospel .
Christian mysticism refers to the development of mystical practices and theory within Christianity . It has often been connected to mystical theology , especially in the Catholic and Eastern Orthodox traditions. The attributes and means by which Christian mysticism is studied and practiced are varied and range from ecstatic visions of the soul's mystical union with God to simple prayerful contemplation of Holy Scripture (i.e., Lectio Divina ).
Progressive Christianity is a contemporary movement which seeks to remove the supernatural claims of the faith and replace them with a post-critical understanding of biblical spirituality based on historical and scientific research. It focuses on the lived experience of spirituality over historical dogmatic claims, and accepts that the faith is both true and a human construction, and that spiritual experiences are psychologically and neurally real and useful.
The Pillars of Islam ( arkan al-Islam ; also arkan ad-din , "pillars of religion") are five basic acts in Islam, considered obligatory for all believers. The Quran presents them as a framework for worship and a sign of commitment to the faith. They are (1) the shahadah (creed), (2) daily prayers ( salat ), (3) almsgiving ( zakah ), (4) fasting during Ramadan and (5) the pilgrimage to Mecca ( hajj ) at least once in a lifetime. The Shia and Sunni sects both agree on the essential details for the performance of these acts. 
Sufism or taṣawwuf ( Arabic : تصوّف ) is defined by its adherents as the inner, mystical dimension of Islam .    A practitioner of this tradition is generally known as a ṣūfī ( صُوفِيّ ). Sufis believe they are practicing ihsan (perfection of worship) as revealed by Gabriel to Muhammad ,
Worship and serve Allah as you are seeing Him and while you see Him not yet truly He sees you.
Sufis consider themselves as the original true proponents of this pure original form of Islam. They are strong adherents to the principal of tolerance, peace and against any form of violence. The Sufi have suffered severe persecution by more rigid and fundamentalist groups such as the Wahhabi and Salafi movement . In 1843 the Senussi Sufi were forced to flee Mecca and Medina and head to Sudan and Libya. 
Classical Sufi scholars have defined Sufism as "a science whose objective is the reparation of the heart and turning it away from all else but God". Alternatively, in the words of the Darqawi Sufi teacher Ahmad ibn Ajiba , "a science through which one can know how to travel into the presence of the Divine , purify one's inner self from filth, and beautify it with a variety of praiseworthy traits".
Jihad is a religious duty of Muslims . In Arabic , the word jihād translates as a noun meaning "struggle". There are two commonly accepted meanings of jihad: an inner spiritual struggle and an outer physical struggle. The "greater jihad" is the inner struggle by a believer to fulfill his religious duties.  This non-violent meaning is stressed by both Muslim  and non-Muslim authors.
The Prophet ... returned from one of his battles, and thereupon told us, 'You have arrived with an excellent arrival, you have come from the Lesser Jihad to the Greater Jihad—the striving of a servant (of Allah ) against his desires (holy war)." 
Buddhist practices are known as Bhavana , which literally means "development" or "cultivating" or "producing"   in the sense of "calling into existence." It is an important concept in Buddhist praxis ( Patipatti ). The word bhavana normally appears in conjunction with another word forming a compound phrase such as citta-bhavana (the development or cultivation of the heart/mind) or metta-bhavana (the development/cultivation of lovingkindness). When used on its own bhavana signifies 'spiritual cultivation' generally.
Hinduism has no traditional ecclesiastical order, no centralized religious authorities, no governing body, no prophet(s) nor any binding holy book; Hindus can choose to be polytheistic, pantheistic, monistic, or atheistic.  Within this diffuse and open structure, spirituality in Hindu philosophy is an individual experience, and referred to as ksaitrajña (Sanskrit: क्षैत्रज्ञ  ). It defines spiritual practice as one's journey towards moksha , awareness of self, the discovery of higher truths, true nature of reality, and a consciousness that is liberated and content.
Traditionally, Hinduism identifies three mārga (ways) of spiritual practice, namely Jñāna , the way of knowledge; Bhakti , the way of devotion; and Karma yoga , the way of selfless action. In the 19th century Vivekananda , in his neo-Vedanta synthesis of Hinduism, added Rāja yoga , the way of contemplation and meditation, as a fourth way, calling all of them "yoga."
Jñāna marga is a path often assisted by a guru (teacher) in one's spiritual practice. Bhakti marga is a path of faith and devotion to deity or deities; the spiritual practice often includes chanting, singing and music - such as in kirtans - in front of idols, or images of one or more deity, or a devotional symbol of the holy. Karma marga is the path of one's work, where diligent practical work or vartta (Sanskrit: वार्त्ता, profession) becomes in itself a spiritual practice, and work in daily life is perfected as a form of spiritual liberation and not for its material rewards.  Rāja marga is the path of cultivating necessary virtues, self-discipline, tapas (meditation), contemplation and self-reflection sometimes with isolation and renunciation of the world, to a pinnacle state called samādhi . This state of samādhi has been compared to peak experience. 
There is a rigorous debate in Indian literature on relative merits of these theoretical spiritual practices. For example, Chandogyopanishad suggests that those who engage in ritualistic offerings to gods and priests will fail in their spiritual practice, while those who engage in tapas will succeed; Svetasvataropanishad suggests that a successful spiritual practice requires a longing for truth, but warns of becoming 'false ascetic' who go through the mechanics of spiritual practice without meditating on the nature of Self and universal Truths. In the practice of Hinduism, suggest modern era scholars such as Vivekananda , the choice between the paths is up to the individual and a person's proclivities. Other scholars suggest that these Hindu spiritual practices are not mutually exclusive, but overlapping. These four paths of spirituality are also known in Hinduism outside India, such as in Balinese Hinduism , where it is called Catur Marga (literally: four paths).
Schools and spirituality
Different schools of Hinduism encourage different spiritual practices. In Tantric school for example, the spiritual practice has been referred to as sādhanā . It involves initiation into the school, undergoing rituals, and achieving moksha liberation by experiencing union of cosmic polarities. The Hare Krishna school emphasizes bhakti yoga as spiritual practice. In Advaita Vedanta school, the spiritual practice emphasizes jñāna yoga in stages: samnyasa (cultivate virtues), sravana (hear, study), manana (reflect) and dhyana (nididhyasana, contemplate).
Sikhism considers spiritual life and secular life to be intertwined:  "In the Sikh Weltanschauung...the temporal world is part of the Infinite Reality and partakes of its characteristics."  Guru Nanak described living an "active, creative, and practical life" of "truthfulness, fidelity, self-control and purity" as being higher than a purely contemplative life. 
The 6th Sikh Guru Guru Hargobind re-affirmed that the political/temporal (Miri) and spiritual (Piri) realms are mutually coexistent.  According to the 9th Sikh Guru, Tegh Bahadhur, the ideal Sikh should have both Shakti (power that resides in the temporal), and Bhakti (spiritual meditative qualities). This was developed into the concept of the Saint Soldier by the 10th Sikh Guru, Gobind Singh. 
According to Guru Nanak , the goal is to attain the "attendant balance of separation-fusion, self-other, action-inaction, attachment-detachment, in the course of daily life",  the polar opposite to a self-centered existence.  Nanak talks further about the one God or Akal (timelessness) that permeates all life  ).  and which must be seen with 'the inward eye', or the 'heart', of a human being.
In some African contexts, spirituality is considered a belief system that guides the welfare of society and the people therein, and eradicates sources of unhappiness occasioned by evil.
The term "spiritual" is now frequently used in contexts in which the term "religious" was formerly employed. Contemporary spirituality is also called "post-traditional spirituality" and " New Age spirituality". Hanegraaf makes a distinction between two "New Age" movements: New Age in a restricted sense, which originated primarily in mid-twentieth century England and had its roots in Theosophy and Anthroposophy , and "New Age" in a general sense, which emerged in the later 1970s
when increasing numbers of people ... began to perceive a broad similarity between a wide variety of "alternative ideas" and pursuits, and started to think of them as part of one "movement"".
Those who speak of spirituality outside of religion often define themselves as spiritual but not religious and generally believe in the existence of different "spiritual paths," emphasizing the importance of finding one's own individual path to spirituality. According to one 2005 poll, about 24% of the United States population identifies itself as spiritual but not religious. 
Modern spirituality is centered on the "deepest values and meanings by which people live." It embraces the idea of an ultimate or an alleged immaterial reality . It envisions an inner path enabling a person to discover the essence of his/her being.
Not all modern notions of spirituality embrace transcendental ideas. Secular spirituality emphasizes humanistic ideas on moral character (qualities such as love, compassion , patience, tolerance, forgiveness, contentment, responsibility, harmony, and a concern for others). : 22 These are aspects of life and human experience which go beyond a purely materialist view of the world without necessarily accepting belief in a supernatural reality or divine being. Nevertheless, many humanists (e.g. Bertrand Russell , Jean-Paul Sartre ) who clearly value the non-material, communal and virtuous aspects of life reject this usage of the term spirituality as being overly-broad (i.e. it effectively amounts to saying "everything and anything that is good and virtuous is necessarily spiritual")  Similarly, Aristotle—one of the first known Western thinkers to demonstrate that morality, virtue and goodness can be derived without appealing to supernatural forces—even argued that "men create Gods in their own image" (not the other way around). Moreover, theistic and atheistic critics alike dismiss the need for the "secular spirituality" label on the basis that i) the term "spirit" is commonly taken as denoting the existence of unseen / otherworldly / life-giving forces and ii) words such as morality, philanthropy and humanism already efficiently and succinctly describe the prosocial-orientation and civility that the phrase secular spirituality is meant to convey but without risk of potential confusion that one is referring to something supernatural.
Although personal well-being, both physical and psychological , is said to be an important aspect of modern spirituality, this does not imply spirituality is essential to achieving happiness (e.g. ). Free-thinkers who reject notions that the numinous/non-material is important to living well can be just as happy as more spiritually-oriented individuals ()
Contemporary spirituality theorists assert that spirituality develops inner peace and forms a foundation for happiness . For example, Meditation and similar practices are suggested to help practitioners cultivate his or her inner life and character. Ellison and Fan (2008) assert that spirituality causes a wide array of positive health outcomes, including "morale, happiness, and life satisfaction.".  However, Schuurmans-Stekhoven (2013) actively attempted to replicate this research and found more "mixed" results.  Nevertheless, spirituality has played a central role in self-help movements such as Alcoholics Anonymous :
if an alcoholic failed to perfect and enlarge his spiritual life through work and self-sacrifice for others, he could not survive the certain trials and low spots ahead 
"Spiritual experience" plays a central role in modern spirituality. This notion has been popularised by both western and Asian authors. Important early 20th century western writers who studied the phenomenon of spirituality, and their works, include William James , The Varieties of Religious Experience (1902), and Rudolph Otto , especially The Idea of the Holy (1917). James' notions of "spiritual experience" had a further influence on the modernist streams in Asian traditions, making them even further recognisable for a western audience.
William James popularized the use of the term "religious experience" in his The Varieties of Religious Experience. It has also influenced the understanding of mysticism as a distinctive experience which supplies knowledge. 
Wayne Proudfoot traces the roots of the notion of "religious experience" further back to the German theologian Friedrich Schleiermacher (1768–1834), who argued that religion is based on a feeling of the infinite. The notion of "religious experience" was used by Schleiermacher to defend religion against the growing scientific and secular critique. It was adopted by many scholars of religion, of which William James was the most influential.
Major Asian influences were Vivekananda and D.T. Suzuki. Swami Vivekananda popularised a modern syncretitistic Hinduism, in which the authority of the scriptures was replaced by an emphasis on personal experience. D.T. Suzuki had a major influence on the popularisation of Zen in the west and popularized the idea of enlightenment as insight into a timeless, transcendent reality.   Another example can be seen in Paul Brunton 's A Search in Secret India , which introduced Ramana Maharshi and Meher Baba to a western audience.
Spiritual experiences can include being connected to a larger reality, yielding a more comprehensive self ; joining with other individuals or the human community ; with nature or the cosmos ; or with the divine realm.
Waaijman discerns four forms of spiritual practices:
- Somatic practices, especially deprivation and diminishment. Deprivation aims to purify the body. Diminishment concerns the repulsement of ego-oriented impulses. Examples include fasting and poverty.
- Psychological practices, for example meditation.
- Social practices. Examples include the practice of obedience and communal ownership, reforming ego-orientedness into other-orientedness.
- Spiritual. All practices aim at purifying ego-centeredness, and direct the abilities at the divine reality.
Spiritual practices may include meditation , mindfulness , prayer , the contemplation of sacred texts , ethical development, and the use of psychoactive substances ( entheogens ). Love and/or compassion are often described as the mainstay of spiritual development.
Within spirituality is also found "a common emphasis on the value of thoughtfulness, tolerance for breadth and practices and beliefs, and appreciation for the insights of other religious communities, as well as other sources of authority within the social sciences." 
The natural sciences have been invested with religious meaning, with antireligious implications and, in many contexts, with no religious significance at all."
It has been proposed that the currently held popular notion of antagonisms between science and religion has historically originated with "thinkers with a social or political axe to grind" rather than with the natural philosophers themselves. Though physical and biological scientists today avoid supernatural explanations to describe reality  , some scientists continue to consider science and spirituality to be complementary, not contradictory, and are willing to debate.
A few religious leaders have also shown openness to modern science and its methods. The 14th Dalai Lama has proposed that if a scientific analysis conclusively showed certain claims in Buddhism to be false, then the claims must be abandoned and the findings of science accepted. 
During the twentieth century the relationship between science and spirituality has been influenced both by Freudian psychology, which has accentuated the boundaries between the two areas by accentuating individualism and secularism, and by developments in particle physics , which reopened the debate about complementarity between scientific and religious discourse and rekindled for many an interest in holistic conceptions of reality. : 322 These holistic conceptions were championed by New Age spiritualists in a type of quantum mysticism that they claim justifies their spiritual beliefs, though quantum physicists themselves on the whole reject such attempts as being pseudoscientific . 
Health and well-being
Various studies (most originating from North America) have reported a positive correlation between spirituality and mental well-being in both healthy people and those encountering a range of physical illnesses or psychological disorders.   Although spiritual individuals tend to be optimistic, report greater social support,  and experience higher intrinsic meaning in life ,  strength, and inner peace ., whether the correlation represents a causal link remains contentious. Both supporters and opponents of this claim agree that past statistical findings are difficult to interpret, in large part because of the ongoing disagreement over how spirituality should be defined and measured. There is also evidence that an agreeable / positive temperament and/or a tendency toward sociability (which all correlate with spirituality) might actually be the key psychological features that predispose people to subsequently adopt a spiritual orientation and that these characteristics, not spiritually per se , add to well-being. There is also some suggestion that the benefits associated with spirituality and religiosity might arise from being a member of a close-knit community. Social bonds available via secular sources (i.e., not unique to spirituality or faith-based groups) might just as effectively raise well-being. In sum, spirituality may not be the "active ingredient" (i.e. past association with psychological well-being measures might reflect a reverse causation or effects from other variables that correlate with spirituality),        and that the effects of agreeableness, conscientiousness, or virtue—personality traits common in many non-spiritual people yet known to be slightly more common among the spiritual—may better account for spirituality's apparent correlation with mental health and social support.    
Masters and Spielmans  conducted a meta-analysis of all the available and reputable research examining the effects of distant intercessory prayer. They found no discernible health effects from being prayed for by others.
Neuroscientists have examined brain functioning during reported spiritual experiences  finding that certain neurotransmitters and specific areas of the brain are involved.  Moreover, experimenters have also successfully induced spiritual experiences in individuals by administering psychoactive agents known to elicit euphoria and perceptual distortions.  Conversely, religiosity and spirituality can also be dampened by electromagnetic stimulation of the brain.  These results have motivated some leading theorists to speculate that spirituality may be a benign subtype of psychosis ().    Benign in the sense that the same aberrant sensory perceptions that those suffering clinical psychoses evaluate as distressingly in-congruent and inexplicable are instead interpreted by spiritual individuals as positive—as personal and meaningful transcendent experiences.  
Spiritual care in health care professions
In the health-care professions there is growing interest in "spiritual care", to complement the medical-technical approaches and to improve the outcomes of medical treatments. For example, Puchalski et al., who argue for " compassionate systems of care", offer the following definition of spirituality in the operationalization of spiritual care:
Spirituality is a dynamic and intrinsic aspect of humanity through which persons seek ultimate meaning, purpose, and transcendence, and experience relationship to self, family, others, community, society, nature, and the significant or sacred. Spirituality is expressed through beliefs, values, traditions, and practices.
However, again the problem here is that numerous atheists such as Arthur Schopenhauer , Bertrand Russell , A.C. Grayling and Aristotle who would personally recoil at being labelled "spiritual" or believers in the supernatural would nevertheless still endorse the pursuit of meaning and purpose and personal efforts to transcend the self. Put frankly, those who term themselves spiritual do not have a monopoly on either compassion or civility. Once the views of such humanist philosophers and the results from psychological surveys are accepted, spirituality seems to boil down to a label given to a particular sub-type from among the broader set of compassionate/civil people.
- Evolutionary origin of religions
- Glossary of spirituality terms
- History of religion
- New Age
- Outline of spirituality
- Perennial philosophy
- Relationship between religion and science
- Timeline of religion
- Sacred–profane dichotomy
- Secular spirituality
- Spiritual but not religious
* Koenig e.a.: "There is no widely agreed on definition of spirituality today".
* Cobb e.a.: "The spiritual dimension is deeply subjective and there is no authoritative definition of spirituality".
- In Dutch: "de hemelse lichtsfeer tegenover de duistere wereld van de materie".
- In Dutch: "de kerkelijke tegenover de tijdelijke goederen, het kerkelijk tegenover het wereldlijk gezag, de geestelijke stand tegenover de lekenstand".
- In Dutch: "Zuiverheid van motieven, affecties, wilsintenties, innerlijke disposities, de psychologie van het geestelijk leven, de analyse van de gevoelens".
- In Dutch: "Een spiritueel mens is iemand die 'overvloediger en dieper dan de anderen' christen is".
- This reference gave rise to the distinguishing of two forms of jihad: "greater" and "lesser". Some Islamic scholars dispute the authenticity of this reference and consider the meaning of jihad as a holy war to be more important. 
- See also Bhagavad Gita (The Celestial Song), Chapters 2:56-57, 12, 13:1-28
- George Feuerstein: "Yoga is not easy to define. In most general terms, the Sanskrit word yoga stands for spiritual discipline in Hinduism, Jainism, and certain schools of Buddhism. (...). Yoga is the equivalent of Christian mysticism, Moslem Sufism, or the Jewish Kabbalah. A spiritual practitioner is known as a yogin (if male) or a yogini (if female)."
- See naturalism