“The New Covenant is a biblical interpretation originally derived from a phrase in the Book of Jeremiah, in the Hebrew Scriptures. It is often thought of as an eschatological Messianic Age or world to come and is related to the biblical concept of the Kingdom of God.
Generally, Christians believe that the New Covenant was instituted at the Last Supper as part of the Eucharist, which in the Gospel of John includes the New Commandment. A connection between the Blood of Christ and the New Covenant is seen in most modern English translations of the New Testament with the saying: "this cup that is poured out for you is the new covenant in my blood".
Christians see Jesus as the mediator of this New Covenant, and that his blood, shed at his crucifixion is the required blood of the covenant: as with all covenants between God and man described in the Bible, the New Covenant is considered "a bond in blood sovereignly administered by God." It has been theorized that the New Covenant is the Law of Christ as spoken during his Sermon on the Mount.”