There are bad as well as good reasons for deciding that one is, or that one should be, an atheist, and I suspect the bad reasons may be more influential. The worst reason for not believing in God (though the least obviously bad), is that there is no evidence for His existence. This is a bad reason for atheism because no-one can agree what would count as evidence. Miracles, scriptures, the testimony of priests and prophets etc, can all be contested on empirical grounds: but for some people the fact that we communicate intelligibly with one another, or that the world is ordered, or even that there is something rather than nothing, is sufficient evidence to demonstrate that there is a Creator who not only made the world but also made it habitable by and intelligible to us. Therefore the appeal to evidence, or lack of it, will always be inconclusive.