Atheism is an antithesis for theism. Theism which is belief in a god or gods is opposite to atheism which is absence of belief in a god or gods. The “a” in a-theism is basically a translation to no-theism. So long as you have a god who you believe in, you are a theist. But if you don’t acknowledge or believe in the existence of a god you are an atheist. If you grow up with no theist belief you become an atheist.
Most atheists have become atheists after opening their eyes to the effects of childhood indoctrination done by religion. I like to call these the enlightened atheists. I’m one of them. I was going to church just because others were. I was praying to a nonexistent entity instead of doing something better with my time. I refused to be sold the fantasy that is religion. Quoting this statement from the Declaration of Independence to describe what it felt like abandoning my religion:
Prudence, indeed, will dictate that governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more predisposed to suffer while evils are sufferable than to right themselves by abolishing the forms they are accustomed.
If these words are not inspirational or motivating to do the impossible, At one point, I was going through mental torture, psychological torture because I thought my doubt was bad and I felt it was too hard to run away from religion. I was more predisposed to suffer in my religion because those evils are sufferable than to go against the beliefs which my society is so accustomed. And whenever I have read this excerpt, I have always gained the courage to abolish the forms that I deemed insufficient to satisfy my skeptical mind.