Wager Argument: "An argument developed by Blaise Pascal that urges an unbeliever to attempt to develop faith in God even if the evidence for God's existence is not decisive. Pascal compared belief and unbelief in God to a wager and pointed out the potential gains and losses each bet holds. If some bet on God and are wrong, they will lose only the paltry pleasure from some sins in this life that they might have enjoyed. If others bet on God and are right, however, they stand to gain eternal bliss. The potential gains and losses are thus staggeringly disproportionate, and Pascal urged the unbeliever to pray, attend Mass and do whatever else may be necessary to develop faith."
Evans, C. (2002) Pocket Dictionary of Apologetics & Philosophy of Religion. Downers Grove, IL: InterVarsity Press.
In his Pensées, Pascal wrote: "Let us weigh the gain and the loss in wagering that God is. Let us estimate these two chances. If you gain, you gain all; if you lose, you lose nothing. Wager, then, without hesitation that He is."