What is the theme of the poem "Death be not Proud" by John Donne?

The central theme of the poem "Death be not Proud" by John Donne is the powerlessness of death. According to Donne, death is but a pathway to eternal life, and as such is not something "mighty and dreadful" as some may believe it to be. Contrary to death's own conception of itself as a forbidding entity powerful enough to destroy and "overthrow," in reality it only brings the best men to a state of "much pleasure" and "soules deliverie." In essence, Donne is telling death that it has no basis for bragging and being "proud," because it is not the ominous, frightening force it would make itself out to be. The speaker's tone is almost belittling; his purpose is to cut arrogant death down to size.

Donne almost seems to poke fun at death's inflated sense of itself, telling it that, in reality, it is a "slave to Fate, Chance, kings, and desperate men." Even in its capability to bring rest it is not the best, because "poppie or charms can make us sleep as well." Death's influence is not final, nor even long-lasting; the speaker says that "one short sleep past, wee wake eternally." Death has not reason to be proud because its power is an illusion, its reign fleeting. Once it has served its purpose of transporting its victims out of earthly life, it is "no more," overcome by life which lasts eternally.