The first reading recalled how God promised that he would make a new covenant with us, and the Gospel pictured Jesus in the weeks when he was preparing to enact that covenant with his blood.
We get a better picture of the New Covenant by looking at the other covenants with which we are familiar. First, we will look at the marriage covenant.
As a priest I have hundreds of times asked a man and a woman, “Have you come here freely, and without reservation to give yourselves to each other in marriage?”
In conclusion I have said, “What God has joined, men must not divide.”
Next, let’s look at the Old Covenant. In advance of it, God said, “You will be my people, and I will be your God.” Then in Chapter Twenty-four of Exodus we read of how that covenant was ratified.
Below Mt. Sinai, Moses had constructed a stone altar to represent God. Then, he had all the people of the twelve tribes assemble on the plain before the mountain. Next, he sent young men to slaughter steers, and to carry in the blood in large brass bowls.
With those preparations made, Moses told the people that if they wanted to enter into a family-like relationship with God, they would need to be like him by observing his commandments. He next called out each of the ten commandments; and as the people were calling out their willingness to observe each of them, the young men passed through the crowd sprinkling everyone there with the steer blood.
The Israelites believed that blood, any blood, was life itself. By their all being sprinkled with blood, they became blood relations of one another.
That rite of sprinkling blood was concluded by the young men pouring the last of the blood on God’s altar, making the Israelites his people, and him their God.
At the Last Supper Jesus said, “This cup is the new covenant in my blood.” Then he asked them if they would keep his commandment, which was that they “love one another, as he had lived them.”