I am sure many homilists today will focus on the Gospel, and rightly so, as we hear the critically important exchange between Our Lord and St. Peter in Matthew 16, where Our Lord refers to Peter as the “rock” on whom He will build His Church.
Here, however, I’d like to focus our attention on the first reading, from the prophet Jeremiah, in which he foretells a new covenant between God and His exiled people (Jer.31:31). God has been gradually forming His people throughout salvation history through a series of covenants, as with Noah, Abraham, Moses, and David. Now Jeremiah foretells a new covenant unlike the others.
God’s law, in the form of the Ten Commandments, was written on stone tablets, instructing the people how to live in right relationship with God. Yet these commandments did not come with the grace to keep them. They were more like instructions for playing a new sport or musical instrument, containing many “thou shall nots.” They were imposed from the outside and the people had to adjust to them, often by trial and error. The commandments seemed burdensome to a stiff-necked people that was not always willing to be taught or led (sound familiar?). As Jeremiah notes, the people were not faithful to their covenant with God (cf. Jer. 31:32).
Jeremiah says that the new covenant will not be a law imposed from the outside, as on stone tablets, but a law on the “inside,” written on the human heart (Jer. 31:31). This new interior law will become part of who they are. They will no longer need “lessons” or tedious practice, as with a sport or an instrument, but rather God’s law will become second nature to them.
With Christ, we see the fulfillment of this prophecy. The law has taken flesh. The Holy Spirit now dwells within us, transforming us. And each time we receive Jesus in Holy Communion, we welcome Our Lord into our bodies and into our hearts, renewing and strengthening the grace we received at Baptism.
Jeremiah says that when the prophecy is fulfilled, the people will “know the Lord” (Jer. 31:34). How well do I know the Lord? Is it evident to those around me that I know the Lord? Do I joyfully welcome God’s law into my heart, or do I offer resistance, preferring my own way instead?
In the Church’s wisdom, we are called today to revisit these and similar questions, as we recommit ourselves to Christ and the Church He founded on the rock.