Death, be not proud, though some have called thee
Mighty and dreadful, for thou art not so....
The unabashedly defiant tone of the these opening lines characterizes the mood of the entirety of "Death, be not proud." The speaker does not fear death, even if others do. From the start, the speaker personifies death, assigning him attributes of a human being, such as pride. The speaker addresses death as an equal, taunting him as not so mighty and fearful as others have said he is. He assumes that Death must be a proud being, because he seems so successful (since everyone dies) and so powerful; but, foreshadowing the Christian theme of resurrection that will emerge later in the poem, the speaker states quite plainly that he has nothing to be proud of.
Thou art slave to fate, chance, kings, and desperate men,
And dost with poison, war, and sickness dwell....
Before even arriving at Christian theology, the speaker tells Death how little control he has: he is the slave, not the master. He can only reap death by chance or fate, and he is dependent on those who kill for his crop. It can't be a good life for him, the speaker says, using a series of words (poison, sickness) that conjure unpleasant images, because he is constantly in the places most people prefer to avoid, such as the battlefield ("war") and the sick room.
One short sleep past, we wake eternally
And death shall be no more; Death, thou shalt die.
Donne's speaker lands his final defiant blow on Death in the poem's last two lines. The last lines assume an understanding of the Christian context of the poem. Death may think he has won, but Christians know death is really only sleep. On the Last Day foretold in the bible, those who are God's children—those who have accepted the salvation of Jesus Christ—will be raised from the grave when Jesus returns to the earth in triumph to gather up the living and the dead. Donne's final lines remind readers of the vision, from the biblical book of Revelation, of the New Jerusalem, where God himself will come to earth and live among his people. At that point, humans will no longer die. Instead, Death will die, because there will be no more death.