If you look at it as a relationship growing and evolving between God and humanity, then it makes sense. The whole idea of a metaphysical God that is omnipotent, omniscient, and omnipresent isn't actually a big part of ancient Jewish belief (it basically came to a fore in the middle ages), and therefore isn't really part of biblical Christian belief.

On top of this, I think that the whole "fulfillment of the law" phrase makes absolutely no sense. It's just the verbiage that's used by Christians when they want to gloss over why they don't have to be doing the whole OT thing anymore. Imagine, ignorance from these people? From what I understand, Phaz was on the right track but missed a little bit of the theological grounding due to the "fulfillment" gloss.

I'll try to explain this as concisely as I can. Pauline Christianity (that is, the Christianity we have now, as based on the letters of Paul), made the theological shift from a Jewish based Christianity, in which Jesus was the Messiah for a small group of Jews, into a universal Christianity, in which you didn't have to be a Jew to be a Christian, and Jesus was a Messiah for the whole world.

This shift was part of the new covenant God was alleged to have made with humanity as a whole, similar to Noah's covenant, rather than just with the Jews. What it said, ultimately, was that the religion was now open for all through the sacrifice of Jesus, and that with the Pentecost, the Holy Spirit descended into the world and made everything both "clean" and "holy." Therefore, there was no longer any need for the Jewish sacrifices or practices, as they were made irrelevant by the new "clean" world.

This all should be taken in the context of all of these people in the early first century believing that the world was going to end at any minute. There's a very clear passage in Paul (I think in Corinthians? I can't remember) that says that people shouldn't be getting married or having sex, period. That it was more or less unideal, because the world was about to end and it's far better to go into the afterlife alone as a singular self.

Secondly, the Pauline doctrines also make commentary on things clean and unclean, pure and impure, and I don't know it all very well, but it doesn't seem to make sense in and of itself in relation to the idea that God's new covenant made everything pure. I don't know if this is particularly relevant or interesting to anyone (I have a feeling there's going to be a lot of tl;dr going on), but it might help.