I'm pretty sure Peer meant the original version of Pascal's Wager, the argument for Christianity, which has the obvious answer, "What if the Muslims are right? or "What if God punishes us for believing?"
That's not an answer, because the probabilities of those things are not equal.
"God punishes us for believing" has a much lower probability, because no one believes it, while many people believe in Christianity.
"Muslims are right" could easily be more probable, but then there is a new Wager for becoming Muslim.
The probabilities simply do not balance perfectly. That is basically impossible.
It has been claimed on this site that the fundamental question of rationality is "What do you believe, and why do you believe it?".
A good question it is, but I claim there is another of equal importance. I ask you, Less Wrong...
What are you doing?
And why are you doing it?