What makes him so difficult? His poems are deceptively simple upon first glance.
Who made the lamb? God made the lamb, and Jesus is the lamb and the lamb is Jesus. The poem reads like a catechism. But what is important to understand about Blake's poetry, is who the narrator of the poem is. In this case, the narrator is a child. The child asks and answers the questions, putting the child in a position of knowledge and power, and removing the adult from the equation altogether.
Blake was a theist; he believed in God and identified himself as a Christian, holding the bible to be the best literature written, but was not a Christian in any traditional or orthodox sense. He believed humans all manifest God and the kingdom of heaven is within all. Blake believed in good and evil, but again, not in any traditional sense. For Blake, the way in which we grasp reality can be evil, evil is in the mind. and we are all responsible for the evil in the world. This is the just the fringes of his beliefs. Blake was a mystic, and had visions of angels and God beginning at a very young age. His theology is so uniquely "Blake-ian", I imagine it would take a scholar years of study to fully understand and be able to explain it.
Now do you see what I mean? Though I found teaching this class very challenging, it was rewarding. When we finally got down to discussing the poems -- we discussed "The Chimney Sweeper"in both Songs of Innocence and Songs of Experience -- the students had wonderful observations and enjoyed dissecting the poems.
If you dare (!) click on the link below and listen to a podcast from a lecture by U.C. Davis Professor Timothy Morton. You will need to download iTunes University to listen. My students listened to it on their own, and then we listened to it together, with a power point presentation I created to help them follow it and explain terms. Please let me know what you think.