In the comments somewhere, the subject of blacks and the priesthood withhin the context of the Mormon church came up; Mormons specificaly disavowed the presence of people with black blood beinig able to reach heaven. Specifically another commentator wondered if other Christian denominations held similar views. Considering the wealth of blues songs which implicitly expect heaven as a potential reward, this seems unlikely. This series of videos is my (kinda wandery, off topic) reply.
Blind Willy Johnson, he wrote the song, as far as I can tell.
Others noticed its awesomeness. Unfortunately, my favorite verion, by Mississippi John Hurt, does not appear to be available through Youtube.
But Nick Cave, who appears to have roughly the same emotional response to the gospels as I (but with, what do you call that? Oh, yeah, talent) has a version.
This is Bukka White (the youtube caption is wrong wrong wrong.) I just love him (at least the itty bits I've heard) and his fine, fine, national guitar. So, an excuse. A random song of his. If I get really really energetic I'll post some of my personal collection, as far as I can tell otherwise unavailable. But, of course, it's all on vinyl.