The Atheist's Wager is an atheistic response to Blaise Pascal's Wager.

While Pascal suggested that it is better to take the chance of believing in a god that might not exist rather than to risk losing infinite happiness by disbelieving in a god that does, the Atheist's Wager suggests that:

You should live your life and try to make the world a better place for your being in it, whether or not you believe in god. If there is no god, you have lost nothing and will be remembered fondly by those you left behind. If there is a benevolent god, he will judge you on your merits and not just on whether or not you believed in him.

What a great philosophy!