When was the new covenant established and what significance does it hold in the context of religious beliefs?

The new covenant was established in Christianity through the teachings of Jesus Christ, who is believed to have initiated it during the Last Supper. This covenant signifies a new relationship between God and humanity, emphasizing forgiveness, salvation, and grace. It is seen as a fulfillment of the Old Testament prophecies and a central tenet of Christian faith, symbolizing the promise of eternal life through belief in Jesus as the Son of God.