"Likewise also the cup after supper, saying, This cup is the new testament in my blood, which is shed for you" (Luke 22:20).
The Greek word diatheke, translated as both "testament" and "covenant," occurs thirty-three times in the New Testament, seventeen of which are in the book of Hebrews. The Hebrew word for "covenant" (berith) comes from a word meaning to "cut, or divide," referring to the fact that blood had to be shed to bind the parties involved to the covenant. (See Genesis 15:10; Jeremiah 34:18-19.) God had made covenants with Abraham and Moses on the part of the people of Israel. He had kept His part of the agreement; but in each case the others involved "continued not in my covenant" (Hebrews 8:9). But God, in His grace, has issued a new covenant.
This covenant or testament is not unlike a human "last will and testament," but there are some differences. He did not merely die, thereby enabling His children to inherit His fortune, but He is now "the mediator of a better covenant" (Hebrews 8:6). He is the sacrifice whose death was necessary to make the covenant binding, and yet He is the "surety of a better testament" (Hebrews 7:22).
He cannot fail, and hence the new covenant cannot be done away with. Through His death, He not only has removed the penalty for our previous failures, but qualified us to receive the inheritance. "For this cause He is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance. For where a testament is, there must also of necessity be the death of the testator" (Hebrews 9:15-16). "Wherefore He is able also to save them to the uttermost that come unto God by Him, seeing He ever liveth to make intercession for them" (Hebrews 7:25). JDM