I don't believe in gods because religion is just tradition, community and ancient mysterious rituals, using people's natural sense of fear, wonder and curiosity, combined with someone's view of "morality" and comforting answers to the "big questions" in a way that ensures the perpetual power and influence of the leaders and the obedience of the followers.

As an outsider, this is obvious with the "gods" of the Norse, Egyptians, Greeks or any of the native American civilizations. The challenge comes in accepting this for the religion you were indoctrinated with, which for me was Christianity.

To me, the Old Testament is nothing more than a bunch of campfire stories of a primitive, brutal tribe of Bronze Age desert nomads. The only reason it became the basis for so much of today's religion is because they famously won all their battles. If any tribe had vanquished the Israelites in any of the battles, our view of religion would probably be completely different. But of course, no one did because the "God" of the Israelites encouraged them to be particularly ruthless and bloodthirsty. "Campfire stories" can be loosely based on truth, but after several generations, will be pretty much unrecognizable, and the whole God part is pure mythology anyway. People love stories of the supernatural, even today, but it doesn't make any of it real.

Meanwhile, the New Testament is just the marketing materials of the followers of a charismatic leader (assuming he existed at all). They had to use all the standard symbolism of the day (being a god, born of a virgin, etc) to give his words the necessary credibility.

We now know that Earth is an insignificant speck in the universe and the only way human beings evolved to the point we did is essentially luck. This is the only life and the only planet we have, our highest aspiration should be to take care of of others and the planet, because there is no one else out there to do it for us.