I wonder how one could not have doubts about the validity of a particular religion when acknowledging the fact that mere coincidence, i.e. the environment where one grew up in, most often is a main determinant of believing a particular religion rather than another. No matter to what extent one being brought up in a particular religious atmosphere may deny, the mind of many such individuals is prone to having a unconscious preference for the religion in question. Therefore, when one attempts to emphasize the inconsistency of having a particular belief being based solely on environment, an answer from such an individual that holds that environment as such hasn't had a profound impact on his or her particular 'choice', but instead was the result after having considered other religions, to some extent cannot be taken seriously. It would be different of course in the case of the former atheist, whose mind wasn't preoccupied by a particular religion in the first place.