Since we have the New Testament, why do we need the Old Testament?
Presbyterians, along with most all other Christians, affirm that both the Hebrew Scriptures (Old Testament) and the New Testament are the Word of God and are essential for the church’s life and belief.
By 150 AD, the church had rejected the views of Marcion, who argued that the Old Testament was not necessary for Christian understanding.
You see, both testaments are vital to understanding who God is and what God has done.
The O.T. is the witness to Israel’s faith in God who liberated the people from Egypt, called them into covenantal relationship, and gave them the Law as a guide for doing God’s will. This God of Israel had made a covenant with Abraham and Sarah to be the God of their descendants and to make them numerous (Gen 17). God’s covenant promises were also made with David, to whom God promised a dynasty (2 Sam. 7:1-17 & 23:5, Ps. 89:3) and it became the messianic hope of Isaiah 11:1-9. Followers of Jesus believe that he is the promised Messiah, from the line of David, and that he in himself fulfills the promises made by God in the various covenants in the Hebrew Scriptures.
There is an important relationship between the two testaments (or covenants); one cannot be understood without the other.
Presbyterians maintain that the “substance” and intent of both the Old and New Covenant are the same, but God’s covenant relationship with the People has been expressed differently over time. The final definitive expression of this covenant relationship is in Jesus Christ, the fulfillment of all God’s promises (Jer. 31:31-34, 1 Cor. 11:23-26).
To read more, check out Don McKim’s book: Presbyterian Questions, Presbyterian Answers. © 2003, 2017 Donald K. McKim. Used by permission of Westminster John Knox Press. All rights reserved.