A number of epistemologists (Sosa, Pritchard, Williamson, et al.) have proposed that "safety" is a necessary condition for knowledge. Here's a generic formulation of the condition:
S knows that P only if S could not have easily falsely believed that P.
(where "S could not have easily falsely believed that P" is often cashed out in terms of not falsely believing P in all worlds nearby the world at which S truly believes that P.)
I'm tempted to think that something like safety is a necessary condition for knowledge, but I'm not interested in discussing the matter here. Rather, for present purposes I'm only interested in exploring whether religious experience is threatened as a basic source of warrant for Christian belief if knowledge requires safety.
Here's a first pass at conveying the worry: it's not uncommon for Christians to attribute widespread error in experience-based religious beliefs to those who have religious experiences that conflict with their own. Here are two common explanations Christian theists offer for the diversity of religious experience:
(i) The religious experiences of those in other religions are caused by the true god, but the interpretive religious framework of those who have them can cause them to easily misconstrue them as experiences of other gods.
(ii) The religious experiences of those in other religions are caused by demons and other spirits, and these are easily mistaken for experiences of the true god (Satan "appearing as an angel of light", and all that).
However, things don't look so easy for the theist when it comes to explanations of type (ii). For Christian scripture states that (ii) is a true explanation of many of the religious experiences of even Christian theists. But if so, then it's hard to see how Christian religious experience could be squared with the safety condition. Or so it seems to me. Thoughts?
 Of course, such a reply would be insufficient in certain dialectical contexts, such as that of aiming to rationally persuade the antecedently unpersuaded that Christian religious experience is authentic.