Pascal’s Wager is a philosophical concept developed by French philosopher Blaise Pascal during the mid 17th Century. The argument is rooted in the concept of game theory and its main premise is that one cannot determine the existence of God through reason alone. Because one cannot use reason and inquiry to prove with 100% certainty that God either exists or does not exists, Pascal concludes that the wise thing and individual should do is to live life as if God does exist. By living such a life, an individual has everything to gain and nothing to lose. If a person lives as though God exists, and they turn out to be correct, they have gained infinite reward in the afterlife.
On the other hand, if God does not exist, an individual has lost nothing. If individuals live as though God does not exist and they are wrong, they have only gained punishment and have lost the potential for a peaceful and happy afterlife. As such, if one weighs the options, clearly the rational choice to live as if God exists is the better of the possible choices according to the logic promoted by Pascal.