Does Divinity = Humanity in Blake?

I think I'm at my first major crossroads in my thinking about Blake (beyond the whole issue of, well, understanding what's going on - a process which is far from complete). I'm putting the finishing touches to a piece of work I have completed on the connections between The Four Zoas and the description of the New Jerusalem in Revelation 21-22. The basic sift of the material I'm fairly happy with, and it has produced some exciting results, especially when the marginalia and Blake's revisions to the text are taken in to account. Rather, I'm struggling with a problem which is at the heart sentences I have produced like this:

"The successive failures of history and contemporary societal movements to effect apocalypse and redemption lead Blake to emphasise all the more strongly that Jerusalem is to be experienced as a transcendental, divine gift."

One of the most difficult things I'm trying to get my ahead around is whether Blake ever really has a theology of transcendence. In the final stages of the poem's revisions, Blake cites John 17:21-23 on the first page of the poem. These words, on a certain reading, essentially state that due to the connections forged between God, Jesus and the disciples, the three take on one identity, and when humanity makes this leap of faith "they may become completely one", meaning that intra-human divisions will be erased, as well as the distinction between humanity and divinity.

How far, for Blake is the "Divine Body" in every man (E663), or how far is it an objective, external reality (as, arguably, it is in orthodox Christian thinking)? If it's the latter, then sentences like mine above aren't problematic, although they do point to a pessimism on Blake's part vis a vis humanity's ability to ever effect on its own the "Universal Brotherhood" the Four Zoas strives towards. If it is the former, however, then speaking of a "transcendental" gift is surely a nonsense, since Jesus is essentially the paradigmatic example of perfect humanity. The power to become him is in all of us, so to speak.

All of this is fairly important because I would like to present The Four Zoas as reflecting the passivity of the vision in Revelation 21-22. John "sees" the New Jerusalem descending from heaven; he doesn't build it himself (like Richard Brothers tried to do). 

In conclusion: gah.