In Scripture, a covenant is a bond that God makes. It is a promise He makes that He confirms with a commitment, an oath.
For example, when He makes a covenant with Noah, He says: “Noah, I am never again going to flood the earth the way I flooded it, and I am not just saying that. I am actually committing Myself to it, and the sign that I am committing Myself to it is the bow in the sky.” We recognize that bow as a rainbow. As some Old Testament scholars have pointed out, the word is “bow,” and if there were an arrow in the rainbow, it would be pointed at the heart of God. That may be an element in what God is saying: “I will keep this promise or I will die.”
The same is true of the Abrahamic covenant, that strange event when Abraham dismembers some animals and then, in the darkness, he sees light passing through them. That is really a symbol of saying that God, who is the covenant maker, is passing through the dismembered animals as an indication that He would dismember Himself rather than fail to keep the covenant. At the heart of these covenants is the promise that God would bring salvation in Christ, which really did mean that He Himself would take the judgment.
So, that’s what is in view: a covenant is a promise that God makes, an oath that He takes, and a life-and-death commitment to fulfill His promise. The glory of the central covenant in the Bible is that it was such a life-and-death commitment to save us that it took the death of Christ to accomplish it.