I can't imagine why any atheist would want to do that.
A religious person is one who, against all reason, has made the decision to believe in a supernatural being for whose existence there is not a scrap of evidence. No doubt he has his unfathomable reasons.
An atheist is merely someone who, for simple, everyday, routine, rational reasons rejects such an idea. My non-belief in God is no different from my non-belief in Santa Claus, fairies and Cinderella. Simple commonsense. It would be just as absurd for me to go back to believing in God (which i did as a child) as to goback to believing in all those other magical things. Why go back into the dark?