What's wrong with Pascal's Wager?

French philosopher and thinker Blaise Pascal freely admitted there was no evidence for the existence of God. But he insisted one would be wise to bet on God’s existence anyway, and be a Christian. His reason was that if you place such a wager and win, you win everlasting life. If it turns out there really is no god, you lose nothing.

Now, on the other hand should you bet on Atheism and win, you win nothing but if you turn out to be wrong, you suffer eternal damnation for your mistake.

So, Pascal’s logic was it is a wager in which you have everything to win and nothing to lose. Now forget for the moment whether Jesus would accept you as a true disciple simply because you coldly chose to hedge your bets. Let us, for sake of discussion, allow that it is a given that Pascal’s Wager will work. What then is the logical error in his thought? Or is he absolutely right?