Blaise Pascal's infamous wager basically asserts (and yes, I'm paraphrasing) that if one doesn't believe in the christian god, and he should happen to be real, one is headed straight to the lake of fire (because he's god, and he loves you like that). However, if one believes in god, even insincerely, you still get a fast pass to the pearly gates.
In short: no harm, no foul.
This may come as a shock to some of you, but I have a bit of an issue with this.
A great many of the same people that use Pascal's wager as evidence that their belief is real (and the only true one) also heap on the "free will" argument. If we assume that Pascal had the right idea (let's call the wager "P"), and you add free will in with it, then P+F should equal heaven... provided you use your free will to believe exactly as you're told. Does anyone else see the problem here?
The main idea behind the christian notion of free will is that you have the freedom to do exactly as you're instructed, or not, whichever you choose. Unfortunately, however, it's difficult for me to wrap my head around the idea of anything being labeled as "free" when there are strings attached. Even when I was four, I'd argue that the prize in a box of Cracker Jacks wasn't actually free.
You know what I do have the freedom to do? Think for myself, form rational thoughts of my own, and not buy the Cracker Jacks. That's free will. It's much more narrowly defined in the real world, and in many cases, the phrase simply doesn't fit. The only thing you truly have the free will to decide is which set of consequences suits you better. When we finally do realize that everything we do comes with consequences of some kind, perhaps we'll start acting a little more responsibly as a species.
I'll see that bet, Pascal, and I'll raise you some science.