It;s not an anomaly to not believe, it's (imo) a developmetal thing. Ancient cultures needed explanations for how the world works and a 'god' concept explained a whiole lot, plus the bonding rituals involved in life and death events kept communities together and therefore safer. Later on, religion evolved to be used by those in power to control their communities. Traditions die hard, as it were, and here we are today.
But as to why I am an atheist:
If god made the world, why? A social experiment e.g. to see if you are good and then punish you when you have no chance to redeem yourself makes no sense. That is not a kind god.
If god can intervene, why do such bad things happen to good and innocent people?
That is not a kind god.
Why does religion ask for belief without proof (i.e. faith)? It's just so convenient. For example, why don't angels appear in the world simultaneously, be filmed, speak to us. They don't. 'Miracles' always happen where they can't be proven.. To me, 'miracles' are merely wish fulfilment. Just as the 'signs' people believe they have seen - coincidence colliding with intention.
Then there is the hypocrisy of the church, the wealth and the abuse. I do not doubt there are many good people of faith, but surely a kind god would not tolerate the existence of the corrupt within its houses?
So we are left with the only realistic concept of any god at all, one that has no interest in our existence and therefore in our behaviour. We can do as we will. And believing all that I have said, I do not think that being an atheist makes me a bad person. I am no more perfect or imperfect than the next person. But I still have morals, love my family, find the world interesting and beautiful, and try to help others. I don't need a god for any of that.The statistics, incidentally, for non-believers vs believers in prison is really interesting - atheists are a tiny proportion overall
I just wish atheists had better community events and organisations - I am slightly jealous of churchgoers for that!