Thinking is associated with material changes and activities in the brain and the connected nervous system. This promulgates the brain-behaviour notion. According to this notion, all aspects of human behaviour and experiences are functions of a material structure, the brain. Who one is, is determined by his or her brain. Nevertheless, many people continue to believe in a 'higher power' that guides and controls human action and behaviour. In a sense, religion and spirituality was developed to understand and explore questions about 'who we are' and 'what is the purpose of life'.

Whether one is Christian, Jewish, Muslim, Buddhist or Hindu, religious thinking and belief attempt to ground human experiences and thoughts in the spiritual and ethereal. Religious experiences are considered 'otherworldly' and not material. Heightened spiritual behaviour through prayer, meditation or yoga is considered to lead to a state of 'transcendence', 'inner peace' or a 'nearness to God' depending on which faith you follow. Hence, the notion of spirituality and religion is based on an ethereal component. However could the ethereal and spiritual be embodied by a material structure, the brain? Recent scientific research has provided observations, which suggest spirituality, and religious experience has a biological basis. Scientific observations suggest there are specific physiological aspects to spiritual behaviour like meditation, prayer, and yoga. 

According to Newberg, the 'human brain is genetically wired to encourage religious beliefs''.  Spiritual experiences like transcendence and inner peace, through meditation and prayer are increased by the activities and interactions of the different areas of the brain and neural networks.

Therefore, is there any 'biological' purpose to such behaviour, if spiritual behaviour and experiences are linked to a material structure, the brain, and the nervous system? Are we literally made for reflection and spirituality? According to Newberg, spirituality has an evolutionary function.   The brain was evolutionary developed for exploring spirituality and religious behaviour.  He argues that spiritual experiences like meditation, and sexual experiences such as arousal and orgasm, though unquestionably not the same experience nevertheless involves similar changes/activities in the neural networks and the brain.

These findings on the material nature of spiritual experiences have created a lot of controversy as well as heightened interest in the society. Many argue that by the machinery of neurobiology of faith, spirituality, religion, and 'God' is dismissed as mere chemical reactions occurring in the brain.

In addition to the studies conducted on accomplished practitioners of spiritual behaviour, observations of patients of temporal lobe epilepsy has revealed specific hyper sensitivity to religious and spiritual behaviour.   All these findings could make atheists and sceptics argue that religion and spirituality are only a dysfunction of the brain.. However, is it possible that it is in reality a 'function' and not a dysfunction of the brain activity?

The activities of the brain and the corresponding nervous system are highly complex and there is still much ambiguity about the actual functioning of the brain. Each brain is supposed to contain approximately hundred billion neurons, which form complex and highly integrated communication networks of hundred trillion neurons.  Some can therefore argue that the workings of the still much unexplored and misunderstood 'gray matter' is influenced by an unexplained ethereal power. There are clearly many limitations to the still infant study of biology of spirituality and faith. For instance, the association of certain spiritual behaviour with brain activity does not specify why some people are more religious and spiritual than others. Nevertheless, these studies produce an important dialogue between science and religion, which can be useful to explore questions about life, behaviour etc. They also advocate an important ground to think about spirituality and religion, irrespective of differences in faith.