Is religious experience reliable?
The view that religious experiences of the kind people normally report are reliable has been a very unpopular philosophical opinion since at least the 19th century. An important change in attitude took place during the second half of the 20th century through philosophers like Richard Swinburne, William Alston and Alvin Plantinga, so that today arguments from religious experience are among the standard set of proofs for the existence of God.
A common starting point in these arguments is the principle of credulity, which roughly says that our experiences, including religious experiences, are trustworthy until there are good reasons to doubt them. Therefore, barring naturalistic or otherwise anti-religious presuppositions, there seems to be no reason to doubt that many religious experiences are in fact truthful.