If we're talking about the words:

Poetry is a line of words, followed by another line of words, that can or can't rhyme. Rap is a line of words, followed by another line of words, that is supposed to rhyme. (although, some of rb's dumbasses such as TRUE*D haven't figured this out yet).

pretty simple. the emotion can be in either. rap can have hatred, poetry can too although not many do. rap can be about love, so can poetry. well this is how i look at it.