The consensus within psychiatry is that patients' religion/spirituality are legitimate topics in assessment and treatment. Religion/spirituality can help people cope with mental illness, but their use as therapeutic tools is controversial. Despite the publication of position statements by national and international psychiatric organisations, there is no clarity over therapeutic boundaries.Declaration of interestR.P. and R.H. are atheists. C.C.H.C. is an ordained Anglican and a past Chair of the Royal College of Psychiatrists Spirituality and Psychiatry Special Interest Group. He writes here in a personal capacity.