"Sweetest Love, I Do Not Goe" by John Donne is a love poem grounded in a deeply religious sensibility. The poem is addressed by a male narrator to a female beloved. The poem begins conventionally, with the narrator explaining that his travel is necessary and not evidence of lack of love. It metaphorically compares separation to a sort of temporary death, and pleads that the beloved not weep or show sorrow, or be afraid that he will be somehow injured, as he will be motivated to return quickly. He reassures her that he will be as constant as the sun that disappears each night but reliably returns the next morning.
What the first four stanzas set up though is a more profound notion that those who are truly in love while alive are not parted in death, but rather end up together in Heaven. Thus the central idea of the poem is that even if he dies on his journey, that is not something to fear, as true lovers will always be together in spirit.