There have always been, and still are, dozens of religions claiming access to God. There are prophets and leaders and teachers and angels, priests and high priests in abundance. What gives any one religious belief the right to claim supremacy over the others?
There could hardly be a more important question and that's what this cumbersome text is addressing. Priesthood, in any religion, is all about getting to God. Priests are all about getting access to God. Our writer picks one such religion thoroughly endorsed by the entire Old Testament - Judaism. And he uses that as an example of how the coming of the Christ makes all religion without Christ and outside of Christ obsolete. And he quite strangely uses this mostly unknown name - Melchizedek - to make his point.