If you wanted to summarize the poem in terms of three arguments, simply put they might be as follows:
- If we had eternity, there would be nothing wrong with your being coy and not wanting to make love with me.
- But we don't have eternity, and one cannot make love in the tomb.
- If we make love now as I want, it will be earth shattering--we will give the sun a run for its money, as they say.
The three "arguments" are organized into stanzas, so they're easy to investigate.
Of course, the whole is much greater than the sum of its parts. Reducing this hyperbolic, intelligent, "metaphysical" poem to an essay-like argument does not do it justice.