The following is a contribution by Ethical Atheist forum user "CounterDax" (Rienk), with minor modifications.
Pascal's Wager
Blaise Pascal (1623 - 1662).We still thank him for his work on hydrodynamics and hydrostatics, including his theory of vacuum. This Frenchman's work, although not limited to physical science, is now part of the physics curriculum all over the world. But, like many of his peers and predecessors, he was also a very religious man, at least for part of his life. He seemed to switch between a less devout lifestyle, to a religious but critical life, all the way to becoming severely influenced by the scripture after a near accident.
This is when he wrote, but never finished, his most influential theological work; a piece of pristine apologetics named the Pensées. But his defense of Christianity showed some Grand Canyon sized gaps and cracks. In Christian apologetics, 'Pascal's Wager', or his so called bet for the existence of God, is often used to point out why it's better to believe in the Lord and his son. Pascal himself wrote: "If you gain, you gain all; if you lose, you lose nothing", making it clear, at least for him, that it's better to worship God.
But let us first break up his wager according to his possibilities. Pascal believed to be for possible outcomes when it came to his vengeful, though loving, God:
According to Pascal, a finite gain or loss is, mathematically, negligible compared to infinite gain or loss. Thus, in his eyes, it was better to believe in God than not to believe in God. Seems solid, but was he right?
Well, Pascal made a lot of assumptions based on the Scripture as he himself interpreted it, not considering other possibilities. For instance, he assumes his God is the only God. But what if God happens to be Shiva or Jhw, or Allah or some ancient God, or even multiple Gods? Let's assume there is only the Christian God, then how likely is it that God punishes the skeptics, the non-believers, even though they have lived a righteous life? God is loving, right? Perhaps there's a God who actually punishes the blind believers - people who only believe because they want to go to heaven, never questioning anything the church says. I say, it would be likely... if God does exist. If we put all these possibilities, and more, in consideration in the Wager, we can perhaps conclude that it's better to believe in any deity granting eternal reward and eternal suffering. But, doesn't the second commandment read: "You shall have no other gods besides Me?" Do not make a sculpted image or any likeness of what is in the heavens above..." - absolute devotion to one God. The same is to be said for Judaism, Islam and many other world religions. Thus, belief in any of these religions does not make sense when fitted to Pascal's Wager.
More striking is Catholicism: by showing repentance and returning to God's vineyards, even just before death, all your sins are forgiven and you are granted eternal life in heaven. Heck, if Hitler showed repentance and did not commit suicide (the final and thus eternal sin) he could be playing cards in heaven according to the Catholic dogma.
There are many other arguments that turn Pascal's Wager in less than "I know you are, but what am I" uttered by a child, but I wanted to finish with one I often use as an argument, though not a good one, myself: Denominations. What if you spend your entire life as a good Mormon, never drinking, always struggling to stay on God's path, and then you die. You reach the gate of heaven, but Saint Peter refuses to open the golden gates to the paradise. "Why?" you ask him while you start sobbing. "I've always lived a righteous and faithful life!" And, Saint Peter answers: "Don't you know? The Catholics were right all along."
Article contributed by "CounterDax" (Rienk).