At first it starts with a nagging question – an inconsistency or a contradiction that you notice in your belief system.
Then you rationalize. It’s usually not that difficult to rationalize – to invent something that makes sense with the rest of your belief system. Your religious beliefs will survive this rationalization – they’ll just have to endure a minor tweak.
Then you have more nagging questions. You realize that even your tweaked belief system is not sufficient to withstand the inquiry of an intelligent mind. Frantically you make more rationalizations and for a time, everything makes sense again.
And then of course you hit upon a new idea and a new question pops up. Once again you rationalize. This process keeps going on for several years. Your belief system gains some patches and a whole lot of little tweaks. Your rationalizations have become quite complex.
At some point you suddenly realize that your beliefs about God are way different from that of everyone else around you. But this is fine, you’re comfortable with this because it makes you feel good to have calmed the cognitive dissonance with your rationalizations.
The questions don’t stop there. In fact, the more you learn about science and philosophy, the more questions you get and the harder they become. You start redefining your beliefs even more. Your God starts becoming smaller and smaller. What you’re doing is learning more and more about the universe and relegating God to the gaps in your knowledge. If you’re lucky, you will have started learning about logic and you will suddenly realize that your beliefs about God are based not on evidence but on arguments from ignorance.
Eventually, you realize that your belief system is the definition of “agnostic”. You don’t tell your friends about your new label but you don’t feel awfully guilty about your beliefs either. After all, what could be the harm in admitting that you don’t know?
Then you start playing devil’s advocate. You debate against your religious acquaintances hoping that they can prove to you that God really exists. They fail miserably.
Mentally you start scoffing at your friends’ beliefs whenever the subject of religion comes up. It is around this time that you realize what you’ve become. An atheist! Surprisingly, it doesn’t feel all that evil. You don’t suddenly have the urge to rape and to kill. Actually, you start feeling better about yourself once you realize that your morality is real and not just a fear of eternal torture.
Becoming an atheist is not a single decision that a person makes nor is it a single point in time. Becoming an atheist is a long journey that often happens over the course of many years. For me it was about 10-12 years from the first serious question I had to when I was first comfortable considering myself an atheist.
Just remember, you were born an atheist!