JERUSALEM : DAN BERN

I was reading some commentary on this song.  Basically, I think people are assuming that this is a love song and that Dan, the singer, is first singing to a woman who wants more of him than he is willing to give.
My interpretation is that, it is the Messiah (be that God or Dan as God) who is singing to YOU.  Don't test my love because maybe I don't love you all that much.