Moorcock’s Behold the Man is entirely different to his Elric books, or Gloriana, or anything else of his I’ve come across so far. Certain people might find it offensive because it undermines the sanctity of Jesus Christ, and tangles that story up in a lot of sexual and mental health hangups. Worse, the figure who becomes Jesus is not altruistic, but self-absorbed and narcissistic.
Still, I think it’s a very interesting way of looking at the story, even if I don’t like the way it portrays Christianity. In a way, it suggests the power of the Christian message: the pure message survives even through a human being’s selfishness and fallibility. The time travel aspect isn’t very prominent, and I don’t think it was really written as science fiction — speculative fiction, yes, but I wouldn’t call it sci-fi. Really, it toys with ideas of identity, predestination, time loops, etc. Technology is not a prominent aspect.
It’s an easy read, actually: I read it in about an hour. If you don’t mind Moorcock playing with basics of Christianity, then you might well find it interesting.