I'd recommend just getting Peter Gabriel's CD if that's what makes this movie for you. I do have the CD and have avoided the DVD. I have seen this movie a couple of times. I agree that the quality is quite bad, but the movie itself is pretty boring, IMHO. I read the book a long time ago and enjoyed it, and was looking forward to the movie. When it first came out on VHS, Blockbuster refused to carry it because there was such an uproar in certain segments of the christian community.
As to whether this follows scriptures or not, it has long been pointed out that very little is actually known of the historical Jesus. The gospels are strangely contradictory in some ways, accenting different aspects of the story for reasons, one would believe, that emphasize the particular areas of the early movement that the individual gospel writers were using to form the church.
If this had been written in the 2nd century, perhaps it would have been one of the "lost gospels" --the accounts of Jesus' life that were intentionally left out of the bible or suppressed like the story of Q.