The "Holy Sonnets" are an example of what is called "devotional poetry," through which the poet tries to demonstrate his or her religious faith. Although the speaker asks to learn how to repent, the poem itself is an act of repentance. "At the round earth's imagined corners" could be compared to a mini-drama, in which the hero falls and begins the path to salvation. Donne draws on his deep knowledge of the Bible to integrate passages from the Book of Revelation and make reference to the Book of Genesis.
The speaker has no reason to wish for the Last Judgment except to witness the pure spectacle of it all; he forgets, however, that he will not be a mere observer to this spectacle and that he too will be judged.
The poem's conception of Christian repentance is deliberately self-contradictory.