Pascal's wager

Named after French theologian Blaise Pascal (1623–1662), who formulated the wager in the Pensées.

1(religion) An argument for theism (and specifically Christianity) maintaining that belief in the divine ensures happiness in this life and offers the possibility of eternal happiness (should God or divine beings exist), whereas atheism, even if it brings happiness in this life, offers no hope of eternal happiness and carries the risk of eternal damnation.