Certainly, there are plenty of people who do lie about these things - for recognition, in lying to themselves, for fun, pathologically or otherwise - and others who exaggerate experience or self-select.

Even taking that into account, there is a tremendous level of consistency with which certain "spiritual" experiences take place. We know that people are sometimes able to exhibit superhuman strength, tossing aside cars and whatnot. Sheer physics tells us this should not be possible. It is common for the dying to see the dead, about a month or so before their own deaths (and thus not part of any "brain death hallucination"). Many people see people at the moment of that person's death in a place the person cannot be (i.e., the "I saw my uncle in the dining room and said, 'How nice of you to visit!' and then when I went to tell my wife, he was gone. My aunt called then and said he had died 300 miles away").

Dismissing all of this as "the world is lying to me" or "people are lying to themselves" is very difficult. The numbers are much higher than, say, alien abduction stories, and so dismissing it as hysteria or schizophrenia or a similar disorder is extremely flippant.

In other words, atheism goes against anecdotal evidence that rises to a level that it cannot be merely discounted and swept under the rug.