Every will or testament is inaugurated with blood according to the biblical economy. When God inaugurated the Old Covenant with Moses, it was signed with the blood of the sacrificial animals. Hebrews 9:19-20 says, “For when every commandment of the law had been declared by Moses to all the people, he took the blood of calves and goats, with water and scarlet wool and hyssop, and sprinkled both the book itself and all the people, saying, ‘This is the blood of the covenant that God commanded for you.’” God promised to “Passover” everyone in Egypt who had applied the blood of the lamb to their doorposts. When the tenth plague came, the first born of every family under the blood signed promise of God were safe. According to the Bible, lambs were the chief sacrificial animal for sins. That began when God offered a lamb and took its skin to make a “covering” (atonement) for Adam and Eve’s sin in the Garden of Eden. When Jesus came into the scene of Hebrew history, John the Baptist declared on several occasions that he was, “The lamb of God that takes away the sin of the world!”
Jesus blood, however, did more than just take away our sin. According to Hebrews 9:15, Jesus sealed the guarantee of a “promised eternal inheritance.” Jesus inaugurated the New Covenant, or signed it, with his blood at his death as the sacrificial offering for sin. All of the Old Testament covenants were inaugurated, signed or sealed with blood. Being “Hebrews” the readers of this epistle were very familiar with the promises of God and the sealing of covenants with blood. Lenski observes, “Since there was so much use of blood in connection with the Mosaic testament and all that pertained to that testament, how can any of the readers find fault with Christ’s death and blood in connection with the New Testament? They should do the very opposite: appreciate the fact that Christ’s death and blood are infinitely more precious than all the Mosaic sacrifices.”[1]
In Exodus 24:8, when Moses sprinkled the blood on the people he accompanied that act with the words, “Behold, the blood of the covenant.” When Jesus took the cup of wine at the last supper he said, “This is the blood of the New Covenant.” Kent observed, “These words were strikingly similar to those of Jesus, ‘For this is my blood of the new covenant, which is shed for many for the remission of sins’ (Matt. 26:28), a similarity of which our author was doubtless well aware.” [2] And Kistemaker says, “Christ shed his blood and thus sealed this new covenant with his blood. His death made the new covenant valid and effective.”[3] Yes, the New Covenant is unbreakable! That’s what Paul told the Galatians as well. One writer put it this way, “Paul was writing to the Galatians who were attempting to improve their standing before God by their own performance. Somehow they had been deceived into thinking they needed to perform certain religious deeds in order to maintain the covenant, or to receive more value from the covenant. Paul’s emphatic response to this thinking is, ‘No, No, No!!!’” (See: https://beingunderthenewcovenant.wordpress.com/2011/06/08/the-unbreakable-covenant/)
[1] R. C. H. Lenski, The Interpretation of the Epistle to the Hebrews and of the Epistle of James (Columbus, OH: Lutheran Book Concern, 1938), 307–308.
[2] Homer A. Kent Jr., The Epistle to the Hebrews: A Commentary (Winona Lake, IN: BMH Books, 1983), 176.
[3] Simon J. Kistemaker and William Hendriksen, Exposition of Hebrews, vol. 15, New Testament Commentary (Grand Rapids: Baker Book House, 1953–2001), 257–258.