Looking more closely at the comments on Leah's conversion announcement post, I find people arguing about whether or not we can have objective morality without a god.
I have to say, I don't think we can really know the answer to this quandary clearly because we either have a God or we don't. And we can only speculate what the world would be like, what morality would be like, if we were in the opposite situation: either without a god in a world with a god, or with a god in a world without a god. Hence, faith enters the picture.
In my mind, it comes down to love. Morality is about love. God who is love, has given to us a sense of morality because he loves us and wishes for us to have joy, and without a moral sense, we cannot really have joy, especially when immorality ultimately separates us from Love.