What is the wager between God and Mephistopheles in Goethe’s Faust?

In Johann Wolfgang von Goethe’s Faust, the traditional diabolical contract is replaced by a cosmic wager between God and Mephistopheles, modeled on the biblical book of Job.12

The wager is not a simple contest over whether Faust will commit evil acts. Instead, it centers on whether Mephistopheles can successfully divert Faust from his ultimate striving toward God. Mephistopheles bets that he can lead Faust astray, while God maintains that a good man, even in his dark impulses, remains aware of the right path.2

Separately, Faust makes his own wager with Mephistopheles: he bets that no matter what earthly experiences the Devil shows him, he will never find a moment so satisfying that he would wish to stop time and remain in it forever. If Faust is ever satisfied—if he says to the passing moment, "Stay, you are so beautiful"—he agrees to forfeit his life and soul. Ultimately, Faust is redeemed in Faust: Part Two because his "constant striving" and the intercession of divine love allow him to transcend his earthly limitations.12