Synonyms: testament, testimony, law, will (bequeathing an estate),
Related ideas: mediator, blood, oath, commandments
Definitions: A covenant is a set of promises with rules and conditions, whereby an agreeable or profitable relationship may exist between two parties. A covenant can be the express will and testament of one party, by which the other party, if compliant, gains an inheritance.
God’s new covenant is a gracious law of promises, requiring obedient faith, mediated to all humans by God’s Son through his blood.
Scripture:
The blood of the new covenant
Matthew 26:28, Mark 14:24 “...my blood of the new covenant...”
Luke 22:20, 1Corinthians 11:25 “...the new covenant in my blood...”
Hebrews 9:19-22, 10:16,29, 13:20 “...the blood of the [everlasting] covenant...”
Mediator of the new covenant
Hebrews 8:6-10 “...the mediator of a better covenant...”
Hebrews 9:15, 12:24 “...mediator of the new covenant...”
1Timothy 2:5-6 “...one mediator between God and man, the man Christ Jesus, who gave himself a ransom for many, the testimony borne at the proper time.” Note: “testimony” here refers to the covenant. Compare Exodus 31:18with Deuteronomy 9:9 where “testimony” and “covenant” are interchangeable terms.
Old and new covenants compared
2Corinthians 3:6-18 “...a new covenant, not of the letter but of the Spirit, for the letter kills but the Spirit gives life.”
Galatians 3:6-29 “...the blessing of Abraham... the promise of the Spirit through faith... Now the promises were spoken to Abraham and his seed... Christ. The law which came 430 years later does not invalidate a covenant previously ratified by God, so as to nullify the promise.”
Galatians 4:21-28 “...an allegory... [Hagar the bondwoman and Sarah the freewoman] are two covenants... ”
Comment: The old covenant mediated through Moses was never meant to be valid within itself. It was meant to foreshadow, and be dependent upon, the covenant to be mediated by Jesus Christ. The "seed" promise to Abraham, centuries before the law of Moses, was in fact a covenant in force which allowed people to be justified by faith. The law of Moses was "added" later, but justification did not come through that covenant, rather it continued to come through faith. The law and the prophets themselves proclaimed this.