A covenant is a relationship or partnership established through a binding agreement. It is one of the central themes of Scripture and understanding the Bible as a whole. In the ancient world, various covenants, treaties, and agreements were common, often made between individuals or nations. However, the covenants we are concerned with are those initiated by God with the people he created—designed for relationship with him and for fulfilling his purpose of renewing the earth.

The Blood of the Covenant

In the Bible, we see that God initiated several covenants, which were almost always sealed with blood. In the Old Testament (OT) these covenants were sealed with the blood of animals but the new covenant (see below) is sealed with the blood of Christ. The importance of the distinction of this new covenant is shown by the fact that the Christian Bible is divided into two main parts – the Old Testament (the word testament means covenant) and the New Testament (effectively, the new covenant). It seems that God always deals with people through covenants.

The Old Covenant

In the Old Testament, God made covenants with several individuals—Adam, Noah, Abraham, and David, for example—but the one most prominently emphasised is the covenant made through Moses with the people of Israel at Mount Sinai (see Exodus 19-24). In this covenant, God gave the people laws to follow, with blessings promised for obedience and curses for disobedience. There was also a provision for a temporary forgiveness of sins through the offering of sacrifices.

In the context of God’s unfolding purpose, sometimes referred to as salvation-history, this covenant, often summarized as “the Law“, served to reveal humanity’s inability to meet God’s perfect standards. It demonstrates that we all fall short of his glorious ideal (see Romans 3:19-24). We all inevitably break the terms of the covenant.

The New Covenant

This is where the good news of the new covenant comes in. Jesus’s death on the cross serves as the eternal sacrifice that deals with our sins once and for all (see Hebrews 9:19-28). This is why, at the Last Supper, he refers to ‘the new covenant in my blood, poured out for you’ when he shares the cup of wine (Luke 22:20). The problem of sin, which could not be fully addressed by the Law or the blood of animals, has been decisively resolved through Christ’s sacrifice.

In addition, under this new covenant it is no longer about us striving to reach God’s standards through our own best efforts. It is no longer about what we manage to do for God but about what God has done for us through Jesus. It is a covenant of grace. We can’t earn God’s favour. In Christ, we already have his favour. Another of the other great dimensions of this new covenant is that God changes us from the inside out. As prophesied in the OT, we get a new heart and a new spirit, and the Holy Spirit comes to live inside of us to enable us to follow God’s laws and commands (Jeremiah 31:31-34; Ezekiel 36:24-27).

Covenant Love

Throughout all of God’s covenants that we read about in the Bible, we see God’s love and faithfulness at work. His love is not fickle and unreliable but strong and unfailing. It is binding. He always keeps his promises. He never lets us down. One of the results of following Jesus under the new covenant, with our sins forgiven and the Holy Spirit transforming us from the inside out, is that we can learn to show the same kind of covenant love. Covenant always relates to the forming of communities and our churches are to be covenant communities bound together with God’s kind of love. We can and should express that love in the way we act towards one another in commitment, integrity, faithfulness and mercy.

There is a helpful summary of the idea of covenant at the Bible Project here.