It is very important, as Christians, to hold on to our Jewish heritage. While a significant part of the New Testament concerns the movement from the old covenant to the new–explaining the differences–it is abundantly clear that the new covenant presupposes the old. They are in continuity with each other. In fact, they can be called, in a certain sense, one and the same.
God made a covenant with a people he chose as uniquely his own. He loved them. He revealed himself to them. He forgave them even when they sinned. In their suffering, He promised them justice. He promised that he would send them his full salvation, blessing even the nations of the world. I repeat the last point–he promised that the whole world would be blessed through them. All this God has done and fulfilled in Christ. We have been blessed through the Jews, as Christ Jesus himself said: “Salvation comes from the Jews.”
Gentile Christians are only wild shoots grafted onto the vine of Israel. This is abundantly evident from the scriptures, the liturgy, and from daily Christian life. Living at the seminary for the past year–praying from the liturgy of the hours each day, studying the scriptures, seeking the Lord–I have begun to identify myself with the Jews (as I understand them from the OT and common knowledge). I can honestly say that I “feel Jewish.”
Christians should know how deep is their Jewish identity when they pour out their hearts to God in the spirit and words of king David in the Psalms, when they cry out to God in their suffering, when they pray the Benedictus or the Magnificat–proclaiming aloud their joy in the messianic fulfillment, when they worship God for his mighty deeds of salvation, when they feel wrapped up in the love of God, when they seek to do the will of God in all things.
The God and Father of Jesus Christ is the God of Abraham, Issac, Jacob, and Joseph. When someone believes in Christ becomes a Christian, they embrace faith in the God of Abraham and Sarah. It is indispensable for each new Christian to be taught the Old Testament, so that they might know the God to whom they are giving over their life (and from whom they are receiving life in return). It all makes me think of the story of the Moabite Ruth, and her words to the Israelite, Naomi: “Your people shall be my people, and your God my God.” When a man becomes a Christian, he says these words to all the people of Israel. This is because he himself becomes an Israelite of the heavenly Jerusalem, and a son of Abraham according faith.