"Death, be not proud" by John Donne

This poem seems to be a religious one simply because of the many references to death not having power. The reason i say this is because many if not all religions describe life after death almost to make the followers ready for death. This makes me believe this to be a poem written by someone who is in the process of losing someone important. He could even perhaps be dying while writing it. In a nutshell, I interpret this poem to be a critcism of death little power in a world with life after death.