Open the Bible anywhere and you are inside a berith — a covenant. It is the spine that holds the whole story upright: God binds himself to a people by solemn oath and blood, and the drama of Scripture is the keeping and breaking and renewing of that bond, until it is sealed forever in the blood of Christ.
Covenants are cut
Hebrew does not “make” a covenant; it “cuts” one. In Genesis 15, animals are cut in two and the parties would pass between the pieces — a walking oath: “may I become like these if I break faith.” The astonishing thing about Abraham's covenant is that God alone passes through, a smoking torch in the dark. The human partner sleeps. God binds himself, and only himself, to keep both sides — covenant as sheer gift, secured by the One who cannot lie.
Sealed in blood
At Sinai the covenant is ratified with sacrifice: Moses throws blood on the people and says, “Behold the blood of the covenant” (Exod 24:8). Covenant and blood are inseparable — the bond is life-and-death serious, sealed at the cost of life. This is the hesed of God taking ritual form: loyal love that commits itself unto blood.
The new covenant in his blood
Israel breaks the covenant again and again, until the prophets promise something new: “I will make a new covenant… I will write my law on their hearts… I will forgive their iniquity” (Jer 31:31-34). On the night he was betrayed, Jesus lifts the cup and says, “This is the new covenant in my blood” (Luke 22:20) — fulfilling Jeremiah, echoing Exodus 24, sealing the new berith not with the blood of bulls but his own. Here justification has its frame: God keeps covenant from both sides at the cross, and the new bond is written on the heart, not just carved in stone.
“This cup that is poured out for you is the new covenant in my blood.” — Luke 22:20
Why it still matters
Covenant is the reason the Bible is one book and not two religions: the same God, the same steadfast love, one unfolding berith from Abraham to Christ. It frames salvation not as a private contract but as adoption into a covenant people; it grounds baptism and the Supper as covenant signs; and it tells us what kind of God we have — not a dealer who strikes bargains, but a King who binds himself by oath and keeps faith to the death.
Where This Word Decides Debates
Berith is foundational to covenant theology and the relation of old and new covenants (continuity vs. discontinuity), to the sacraments as covenant signs (baptism, the Supper), to infant vs. believer baptism debates, and to the unity of the Testaments. The diathēkē/“testament” rendering shapes how grace and covenant relate.
When This Word Study Proves Too Much
Do not read covenant as a contract between equals — the LXX's diathēkē (testament/will) marks it as God's one-sided, self-binding gift, especially in Genesis 15. Do not sever covenant from blood and sacrifice; the bond is sealed at the cost of life. And do not set covenant against grace: God's covenants are grace given binding form, not bargains that earn his favor.