How can this be? But you're such a good person!

I've always wondered how prejudices form.  We all have a personal story of someone in our life that we got a bad first impression of only to find out that they weren't so bad or mean to begin with.  The feelings of guilt and regret and the questions start to run through your mind, "Why did I judge them so quickly?  What made me believe this person was bad?  Why does everyone feel so negative about this person?"

Recently, a friend of mine said that even though I'm an atheist, she still considers me a great person.  On first glance, it's a very nice thing to say, but at second glance there's a connotation that being an atheist implies being a "bad person".  Almost all of my friends, family, and co-workers would say I'm a good person.  How do they know this?  Because they have gotten to know me.  They have known me long enough to know I wouldn't steal, maliciously kill, intentionally lie (in most cases), or harm others.

I know that I don't need a deity that watches over everything I do and say and who will send me to eternal punishment if I break one of his rules that comes from a really old book.  I am a good person without a god/gods.  Most believers are good people with a belief in a god/gods.  Most of us are good people.  Why do most americans think I need a god to be the person I was raised to be?  I am a good person, period.  Why?  Because it's the right thing to do, not because I fear eternal punishment or have selfish want of an eternal life.  I am good for the sake of being good.  If that's enough for me, shouldn't that be enough for everyone else?