George Smith takes another angle on it, calling it the Atheist's Wager. Live your life as an atheist. If god does not exist, it won't make any difference; if god exists, but is just, you have nothing to fear; and if god exists but is unjust, you have much to fear, but so does the Christian.
It's a quote from Marcus Aurelius:
Right, I'm familiar with that one. Smith says somewhat the same thing, but it's kind of different in that (among other things) he goes into more detail about it.
I want to offer you a kind of counter-wager, called the "Smith's wager." Here are the premises of my wager:
1. The existence of a god, if we are to believe in it, can only be established through reason.
2. Applying the canons of correct reasoning to theistic belief, we must reach the conclusion that theism is unfounded and must be rejected by rational people.
Now comes the question, "But what if reason is wrong in this case?", which it sometimes is. We are fallible human beings. What if it turns out that there is a Christian god and He's up there and He's going to punish for eternity for disbelieving in Him. Here's where my wager comes in. Let's suppose you're an atheist. What are the possibilities? The first possibility is there is no god, you're right. In that case, you'll die, that'll be it, you've lost nothing, and you've lived a happy life with the correct position. Secondly, a god may exist but he may not be concerned with human affairs. He may be the god of traditional Deism. He may have started the universe going and left it to its traditional devices, in which case you will simply die, that is all there is to it, again, and you've lost nothing.
Let's suppose that God exists and He is concerned with human affairs -- He's a personal god -- but that He is a just god. He's concerned with justice. If you have a just god, he could not possibly punish an honest error of belief where there is no moral turpitude or no wrongdoing involved. If this god is a creator god and He gave us reason as the basic means of understanding our world, then He would take pride in the conscientious and scrupulous use of reason the part of His creatures, even if they committed errors from time to time, in the same way a benevolent father would take pride in the accomplishments of his son, even if the son committed errors from time to time. Therefore, if there exists a just god, we have absolutely nothing to fear from such a god. Such a god could not conceivably punish us for an honest error of belief.
Now we came to the last possibility. Suppose there exists an unjust god, specifically the god of Christianity, who doesn't give a damn about justice and who will burn us in Hell, regardless of whether we made honest mistakes or not. Such a god is necessarily unjust, for there is no more heinous injustice we could conceive of, than to punish a person for an honest error of belief, when he has tried to the best of his ability to ascertain the truth. The Christian thinks he's in a better position in case this kind of god exists. I wish to point out that he's not in any better position than we are because if you have an unjust god. The earmark of injustice is unprincipled behavior, behavior that's not predictable. If there's an unjust god and He really gets all this glee out of burning sinners and disbelievers, then what could give him more glee than to tell Christians they would be saved, only to turn around and burn them anyway, for the Hell of it, just because he enjoys it? If you've got an unjust god, what worst injustice could there be than that? It's not that far-fetched. If a god is willing to punish you simply for an honest error of belief, you can't believe He's going to keep his word when He tells you He won't punish you if you don't believe in Him because He's got to have a sadistic streak to begin with. Certainly He would get quite a bit of glee out of this behavior. Even if there exists this unjust god, then admittedly we live in a nightmarish universe, but we're in no worse position than the Christian is.
Again, if you're going to make the wager, you might as well wager on what your reason tells you, that atheism is correct, and go that route because you won't be able to do anything about an unjust god anyway, even if you accept Christianity. My wager says that you should in all cases wager on reason and accept the logical consequence, which in this case is atheism. If there's no god, you're correct; if there's an indifferent god, you won't suffer; if there's a just god, you have nothing to fear from the honest use of your reason; and if there's an unjust god, you have much to fear but so does the Christian.