Jeremiah 31:33
"But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people."
The pinnacle of prophetic covenant promise. The old covenant was written on stone — external, distant, breakable. The new covenant writes God's law on the heart itself. This verse, quoted three times in Hebrews, explains the entire difference between law and grace.
Hebrews 8:6
"But now hath he obtained a more excellent ministry, by how much also he is the mediator of a better covenant, which was established upon better promises."
Every word here is carefully chosen. The new covenant is not merely different from the old — it is better in every measurable way: better mediator, better foundation, better promises. Jesus is not a replacement for the old system; he is its fulfillment and its surpassing.
Genesis 17:7
"And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee."
God uses the word "everlasting" — this covenant has no expiration date. The promise made to Abraham flows through Isaac, Jacob, and ultimately to Christ, the true seed (Galatians 3:16), and then to all who are in Christ. It has never stopped being in force.
Matthew 26:28
"For this is my blood of the new testament, which is shed for many for the remission of sins."
At the Last Supper, Jesus identifies the cup with his own blood — the covenant seal. Just as ancient covenants were ratified with blood, the new covenant is ratified with the blood of God himself. Every communion table is a covenant renewal ceremony.
Isaiah 54:10
"For the mountains shall depart, and the hills be removed; but my kindness shall not depart from thee, neither shall the covenant of my peace be removed, saith the LORD that hath mercy on thee."
God stakes his covenant on something more stable than the geology of the earth. When Isaiah says the mountains might move before God's kindness fails, he is making the most audacious statement of covenant faithfulness in all of Scripture. This is security that cannot be shaken.
Hebrews 13:20
"Now the God of peace, that brought again from the dead our Lord Jesus Christ, that great shepherd of the sheep, through the blood of the everlasting covenant..."
The resurrection is here described as a covenant act. God raised Jesus "through the blood of the everlasting covenant" — meaning the cross and empty tomb are the covenant's ultimate fulfillment. The God who keeps covenant is the God who conquers death.