Atheism, stoicism

I was at a football-watching party the other day, and I heard a person mention in a disdainful tone that someone was an atheist.
I stopped and butted in with, "What's wrong with being an atheist? I'm an atheist."

(Truthfully, I may still be an agnostic, altho lately I've been thinking of converting.)

The woman paused a second, apparently surprised that she was at a party with a non-believer. Then she said, "Why?"
I was at a loss for words (a rarity). I just shook my head and started to walk away. Later I thought, the question is, why believe?

I used to be a believer, but only because those beliefs were handed down to me by my family. I no longer believe in god or religion, only in an order in the universe, one worth trying to live in harmony with.

I like stoicism's wisdom:
One should live in harmony with the world,
bear the blows of fortune calmly,
and recognize character as one's only true possession.

And be here now.