I would add that (as mentioned above), the represented fall from grace is important to the poem. There is a form a idolatry to the "angel" allowing himself to love too much and in the wrong way the one "made of clay".
It seems that he knows better, but throws caution to the wind, and it ends as he knew it must.
I think that, if the "made of clay" element were removed, so would much of the significance of the fall. However, it still seems arrogant to have up that kind of value separation between himself and the girl.