Excerpt from Chapter 6 of the book, Without a Doubt, by Kenneth Richard Samples.
Blaise Pascal, 1623-1662, was a French mathematician, physicist, inventor, writer and philosopher. He is probably best known for [his Pensées, and for] his presentation of the wager argument for faith in God. His intended audience for this voluntaristic argument (an appeal more to the human will than to reason itself) was his skeptical friends who remained simultaneously unconvinced by the claims of atheism, skepticism, and Christianity.
He believed that the existential realities of life force human beings to make decisions concerning such ultimate issues as what await one in death. The uncertainties and risks inherent in the human predicament force one to make up their mind about God’s existence. How one decides this ultimate issue has potential consequences in this life, and possibly in the next. For Pascal, the question of God’s existence and the truth of the Christian religion cannot be decided by an appeal to reason. For him, "There is too much to deny and too little to be sure." Therefore people must make a prudent wager about whether God does or does not exist. He writes in the Pensées:
Either God is or he is not. But to which view shall we be inclined? Reason cannot decide this question. Infinite chaos separates us. At the far end of this infinite distance a coin is being spun which will come down heads or tails. How will you wager? Reason cannot make you choose either, reason cannot prove either wrong…. You must wager. There is no choice, you are already committed. Which will you choose then? Let us see: since a choice must be made, let us see which offers you the least interest.
For Pascal there are two possible wagers. The first is to wager on God by believing in God and making a religious commitment (for Pascal this is, of course, the Christian God). Two possible outcomes can result from wagering on God. One’s belief can be correct or incorrect. If one believes in God and God actually exists, then according to Pascal the believer stands to gain everything. The payoff, so to speak, for wagering correctly would involve an infinite gain (eternal life with God, heaven). On the other hand, if one believes in God and God does not actually exist, then the believer loses nothing. In terms of a cost – benefit analysis, the one who wagers on God has everything to gain and nothing to lose.
The second wager is to wager against God by not believing in God and refusing to make a religious commitment. Two possible outcomes can also result from wagering against God. One’s disbelief can also be correct or incorrect. If one does not believe in God and God does not exist, then the unbeliever gains nothing. On the other hand, if one does not believe in God but God does actually exist, then the unbeliever stands to lose everything. The loss for wagering incorrectly would involve an infinite loss (eternal exclusion from the life of God, hell). In terms of a cost – benefit analysis, the one who wagers against God has nothing to gain and everything to lose.
In light of these two scenarios, Pascal asserts that the prudent wager is to wager on God! For Pascal, adopting Christianity over atheism is a judiciously rational decision.
Let us weigh up the gain and the loss involved in calling heads that God exists. Let us assess the two cases: if you win you win everything, if you lose you lose nothing. Do not hesitate then; wager that He does exist.
[Editor's note: In the chapter goes on to clarify the wager and discuss various criticisms that have been leveled against it.]