Summary: There are not two covenants, or two fulfillments; Jesus fulfills the covenants with Abraham, Moses and David
The New Testament is the completion of the old. The New Covenant in the blood of Christ, which we re-present at this hour, is the fulfillment of the Old. We forget this important reality at our peril, because it leads us to either pass by our indebtedness to our older brothers, the Jews, or, like certain preachers, think that the Old Covenant needs further fulfillment, and that it has the power to save the Jews. So, for instance, these preachers spend millions of dollars scouring the earth for Jews to send to Israel, and back the theft of Palestinian land by the Israeli developers who are fighting tooth and nail to throw all the Palestinians out of their own land. All that because they think God wants the Jews to occupy the land between Egypt and Iraq, and rebuild the Jewish Temple after destroying the Al Aqsa mosque, thus bringing on World War III and forcing the second coming of Christ.
All that is futile, because the covenant with Abraham, and the covenant with Moses, and the covenant with David–all three are fulfilled in the person of Jesus Christ and in the reality of the Catholic Church. There are not two divine plans–just one–and we celebrate it right here in the Eucharistic banquet, the earthly representation of the wedding banquet in heaven.
Now consider today’s readings. Some folks think that Jesus brought an entirely new teaching with the Sermon on the mount. But look at Isaiah’s teachings: feed the hungry, shelter the homeless, clothe the naked, free the prisoner. Are these not the corporal works of mercy? Doesn’t the command to loose the bonds remind you of the injunction to admonish sinners in the spiritual works of mercy?
The command to love God and love our neighbor is not new to Jesus. It comes right from Torah. The Pharisees had finessed that fundamental law right out of everyday life, but Jesus not only showed us that we can’t live without it, he took it to the limit when he loved us all the way to giving himself on the cross, and continuing to give us His own life in this sacrament of love.