My family used to go to church whenever grandpa would visit us. It was boring and I never paid any attention to the sermon. We never went to church on our own, and by the time I would've been old enough to listen and ask questions, we started visiting grandpa instead. We didn't end up going to his church for whatever reason. All my knowledge of God came from family and pop culture. To this day I still haven't read the Bible, so most of the stuff that's in there didn't factor in my decision.
In my early teens I began wondering why bad stuff happens to good people. How natural disasters kill indiscriminately and have nothing to do with the nature of evil. About how contradictory omnibenevolence is when you get sent to hell for not believing in Him, when He answers no prayer, nor gives any evidence of His existence. I decided either God must forgive people of their sins, or He is a tyrant unworthy of worship.
I came to realize God was no more credible than the magical Santa Claus I'd already learned wasn't real. My science classes taught me rational explanations for the origin of life that didn't require an intelligent creator to build our flawed bodies. I decided life was too short to waste praying to a nonexistent entity. Also, now I don't need to worry that somebody's always watching me poop (hopefully.)
I later learned about how brain damage can drastically affect one's memory, personality, and awareness. If so much is determined by the brain, that doesn't leave much left for a soul. After a while I came to terms with the fact that we'll all cease to exist when we die, and nothing we do will matter by the heat death of the universe. I've resolved to just try to enjoy life and will probably have my body cryonically preserved in the off chance the "self" can survive a restart of the brain, so that I can continue to exist for a few more millennia.
Maybe some people need a god to give them morals or a reason to exist, but I've realized I don't have a spiritual side. Maybe some day it'll try peyote or something to "expand my consciousness" or whatever, but I'm not in any particular rush to go out and eat my mushrooms acquire some drugs.