New Covenant Theology is a system of theology that explains how the bible fits together. It does so by explaining three areas of biblical truth. They are COVENANTS, ISRAEL, and LAW.
Regarding COVENANTS NCT teaches that the Noahic Covenant guarantees that this earth will remain until God’s plan of salvation is accomplished. The Abrahamic Covenant is the unveiling of God’s plan to have a people and take them into his land. This covenant embraces both the Old and New Covenants. The Old Covenant is a works covenant that produces a people (Israel) who are a temporary, unbelieving picture of the people of God. This covenant functions as a picture. The New Covenant is a gracious covenant that addresses the work of Jesus Christ on the cross. Jesus paid for the sins of all those whom the Father chose to save. This covenant functions as the fulfillment. Jesus also secured a transforming work of the Holy Spirit for those whom he died. Finally, there is the Davidic Covenant. This covenant guarantees a king over Israel. This covenant is ultimately fulfilled by Jesus Christ, the King of Kings who is the king over spiritual Israel, the true people of God.
Regarding ISRAEL the Old Covenant produced a physical Israel (an unbelieving picture of the people of God). There has always existed a remnant of believers within Israel. Physical Israel is replaced in God’s plan (the New Covenant) by spiritual Israel, the church, which Is made up mostly Gentile believers with a remnant of Jewish believers. The land promise to Israel, the Promised Land, is a temporary picture of a land promise that will never end, eternal life (the new heavens and new earth).
Regarding LAW, NCT teaches that the Mosaic Law has come to an end with the close of the Old Covenant era. In the New Covenant era (Pentecost until the 2nd Coming) we are now under a different version of law called the Law of Christ. This version of God’s law brings over some laws of the Mosaic Law into the Law of Christ. What was sin in the Old Covenant era is not necessarily sin in the New Covenant era. The Ten Commandments are a summary of the requirements of the Old Covenant, a works covenant. Though nine of the Ten Commandments are included in the Law of CHRIST in one form or another, The Ten Commandments as the ten are not the summary of what God requires of us in the New Covenant era.