"He is the mediator of a new covenant, in order that … those who have been called may receive the promise of the eternal inheritance. For where a covenant is, there must of necessity be the death of the one who made it. For a covenant is valid only when men are dead, for it is never in force while the one who made it lives" (Hebrews 9:15-17, New Amer. Stand.).
Because Christ's blood can cleanse from dead works (Heb. 9:14), the inheritance contained in God's promise is assured to His people. Having spoken in verse 15 of the "inheritance," the author's mind seems to move for a moment to a double meaning possessed by the word which he has been using for "covenant." For the word here translated by the King James Version as "testament" is the same word translated it covenant" in chapter eight of Hebrews (the New American Standard correctly shows this). Because the English language needs two words to express what the Greek language could say with this single word, the English reader is at a disadvantage in following the writer's argument here until he learns this double sense.
Ordinarily in Scripture, this Greek word (diatheke) means "covenant." It is a basic and very important word in the Old Testament, where it stands for the Hebrew word (B'rith) signifying the divine disposition or arrangement imposed by God on the nation of Israel, through which He brought Israel into a special arrangement and relationship with Himself. That "covenant" was one-sided in that God planned and expressed it and Israel could not bargain the terms. But it was two-sided in that Israel accepted certain stated conditions involving both blessing and punishment (see Ex. 24; Deut. 27-30).
In New Testament times, however, this same Greek word was commonly used for a last will and testament (in the Oxyrhynchus Papyri, for example). Not only so, the word for the man who offered a covenant was the same word used for the man who made a will. There are similarities and differences between these two concepts. A covenant and a will have in common that both (at least in a divine-human covenant) involve a death. They are distinct inasmuch as such a covenant provides for both benefits and punishments, but a will provides only for benefits-which are guaranteed by the death of the man who makes the will.
In verses 15-20, the word is used both ways. Verses 15, 18-20 use this word in the usual Biblical sense of a "covenant." But verses 16-17 use the same word (as it was commonly used when Hebrews was written) of a "will." By this careful shift in emphasis from one to the other and back again, the author points out a special benefit of the new "covenant" which the old could not give.
The point in verses 16-17 is not that Jesus was free during His lifetime to dispense blessings in a manner other than that provided for in His "will," although it is certainly true that "the Son of man" had "power on earth to forgive sins." Rather the author's concern is that a death must take place in the establishment of either a divine covenant or a human will, and that, in the case of a "last will and testament," once the death has occurred the benefits provided by the will are guaranteed to the beneficiaries.
Because Christ's death can purge the conscience from dead works, His beneficiaries will receive the eternal inheritance. His new "testament" is of the nature of a "will," as well as that of a "covenant," but as a will it provides only benefits!
This does not diminish the force of such stern warnings as this epistle contains regarding apostasy or unfaithfulness. Individuals are rather to exhort one another lest any be hardened (3:13). Some who once entered the covenant may be lost, though only through failure to remain in the covenant by faith (fullness). All who remain among the covenant people will obtain the blessings secured by Christ's death, for His death was that of a "testator" as well as that of a "covenant-mediator."