This paper analyses a number of possible reasons why modern psychiatry has neglected the therapeutic effects of religious beliefs. The gap which exists between psychiatry and religion is a relatively recent phenomenon and is partly related to psychiatry's progress in elucidating the biological and psychological causes of mental illness, rendering religious explanations superfluous. In addition, it is often assumed that religious attitudes are inevitably linked with phenomena such as dependence and guilt which are frequently seen as undesirable. Psychiatrists and psychologists tend to be less religiously orientated than their patients, which may further increase the professional's idea that religious beliefs are associated with disturbance. However, it has long been suspected that a positive relation exists between religion and mental health, and recently, the psychology of religion has provided empirical support for this idea. Psychiatry faces the challenge to accommodate this evidence into theory and practice.