When I read the Old Testament I am amazed that the God of all, the Creator of the universe, the great "I Am" established Himself among mankind. He walked with them, He talked to them, He fought their battles, and He promised His welfare and protection over them. He said that if they would listen and follow His commands that He would be their God and they would be His people.
However, as overwhelming as all of that was, along came the New Testament and God the Father upped the Covenant. He gave us a new and better Covenant than the one of the One Testament saints and followers.
It was a "MUCH MORE" Covenant.
It was a Covenant that moved the priesthood from mere man here on earth, to our Lord Jesus Christ seated at the right hand of the Father.
Hebrews 8:1-7 ESV Now the point in what we are saying is this: we have such a high priest, one who is seated at the right hand of the throne of the Majesty in heaven, (2) a minister in the holy places, in the true tent that the Lord set up, not man. (3) For every high priest is appointed to offer gifts and sacrifices; thus it is necessary for this priest also to have something to offer. (4) Now if he were on earth, he would not be a priest at all, since there are priests who offer gifts according to the law. (5) They serve a copy and shadow of the heavenly things. For when Moses was about to erect the tent, he was instructed by God, saying, “See that you make everything according to the pattern that was shown you on the mountain.” (6) But as it is, Christ has obtained a ministry that is as MUCH MORE excellent than the old as the covenant he mediates is better, since it is enacted on better promises. (7) For if that first covenant had been faultless, there would have been no occasion to look for a second.