Pascal says that it is impossible to prove or disprove God's existence, and so our choice of whether or not to believe in Him should be based on the benefits, costs, and odds of making the right choice. If God does not exist, then all of the benefits and costs are earthly ones; if He does exist, then there will be heavenly consequences as well.

Pascal assigns equal probability to the possibilities that God does or does not exist ("the game is being played for even odds"), and says that any heavenly rewards will be infinitely greater in magnitude than earthly costs "the prize here is an infinity of infinitely happy life". Given this situation, the only rational choice is to bet that God exists.

I think that probability theory would say that if the risk/reward matrix that Pascal proposes (uncertain infinite gain vs. certain finite loss) is correct, then we ought to bet on God (whatever the odds are). So it does seem here that we have a response for the moral sceptic: an answer to the question "what's in it for me?".

However, one objection to this argument is that if we have no way of knowing for certain whether God exists, then we have no way of knowing for certain what He has lined up for us after we die - perhaps it's not an infinity of happiness. Or perhaps we don't have to commit our lives to God in order to enjoy it - we have no way of knowing what occupies the result box for "don't believe in God but He does exist".

Pascal seems to be be thinking of a Christian God, but others are on offer; how are we to know which one to gamble on? And in any event, the Bible says that salvation for Christians is a matter of faith, not what actions you take (Eph.2:8-9 "you have been saved through faith; and this is not your own doing, it is the gift of God - not because of works"). I can't make myself believe in something, even if I can make myself live my life as if I did.