Jesus our Great High Priest is Mediator of the New Covenant
Hebrews 8:6-13 (NIV84)
6) But the ministry Jesus has received is as superior to theirs as the covenant of which he is mediator is superior to the old one, and it is founded on better promises. 7) For if there had been nothing wrong with that first covenant, no place would have been sought for another.
8) But God found fault with the people and said: "The time is coming, declares the Lord, when I will make a new covenant with the house of Israel and with the house of Judah. 9) It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, because they did not remain faithful to my covenant, and I turned away from them, declares the Lord.
10) This is the covenant I will make with the house of Israel after that time, declares the Lord. I will put my laws in their minds and write them on their hearts. I will be their God, and they will be my people. 11) No longer will a man teach his neighbor, or a man his brother, saying, 'Know the Lord,' because they will all know me, from the least of them to the greatest.
12) For I will forgive their wickedness and will remember their sins no more." 13) By calling this covenant "new," he has made the first one obsolete; and what is obsolete and aging will soon disappear.