Louise M. Antony contemplates it:
Suppose that you do something morally terrible, something for which you cannot make amends, something, perhaps, for which no human being could ever be expected to forgive you. I imagine that the promise made by many religions, that God will forgive you if you are truly sorry, is a thought would that bring enormous comfort and relief. You cannot have that if you are an atheist. In consequence, you must live your life, and make your choices with the knowledge that every choice you make contributes, in one way or another, to the only value your life can have.
Some people think that if atheism were true, human choices would be insignificant. I think just the opposite — they would become surpassingly important.
The Dish 