In Hebrews 7:18-19, we read that Jesus gives us a better hope than trying to rely on our own works to bring us closer to God. Our righteousness is sketchy at best. His is perfect. If we place our hope in our own behavior we all fail, but Jesus gives us a better hope with respect to our destiny. The writer then goes on to say that this is a sure thing. It’s established once and for all by God’s promises. Hebrews 7:20-21 says, “And it was not without an oath. For those who formerly became priests were made such without an oath, but this one was made a priest with an oath by the one who said to him: ‘The Lord has sworn and will not change his mind, you are a priest forever.’” I like what Pfeiffer says, “This fact should encourage the Christian. In the midst of the changing world, he trusts the changeless Christ who holds His office by virtue of the unalterable Word and will of God.”[1]
There was no promise to Aaron and the Levitical priests regarding the duration of that office. It was always intended to be supplanted by a better one when the Messiah came. He would not only be the King but would also be the one and only High Priest forever. Since there was no mention by God of the duration of the Levitical Priesthood, it is obviously inferior to the one established with an eternal promise. The oath that the author of Hebrews is referring to is recorded in Psalm 110 which has become the basis for much of the discussion regarding Melchizedek. In verse 4 we read, “The LORD has sworn and will not change his mind, ‘You are a priest forever after the order of Melchizedek.’”
The argument is that when God speaks, that’s enough! Why did he feel it necessary to add an oath to his proclamation concerning the Messiah’s role as an eternal High Priest? Kent Hughes quotes from two commentators who help explain this phenomenon. “’An oath was not necessary, because God’s word is enough. But because humanity is a race of liars, God accommodated himself within the sphere of human undependability.’1 His oath is a double-assurance to fallen, duplicitous humanity of the eternality of Jesus’ Melchizedekian priesthood. Whatever ‘God confirms by an oath becomes something so utterly unchangeable that it is woven into the very fibre of the universe and must remain forever.’” 2 [2] No set of rules or rituals will ever satisfy our souls or make us acceptable to God. It’s only the intercessory work of Jesus that will suffice. Stedman concurs saying, “The old covenant will no longer work and no secular or pagan solution to the problem of sin and spiritual immaturity is acceptable.”[3]
[1] Charles F. Pfeiffer, The Epistle to the Hebrews, Everyman’s Bible Commentary (Chicago, IL: Moody Press, 1962), 64.
1 Philip Edgcumbe Hughes, A Commentary on the Epistle to the Hebrews (Grand Rapids, MI: Eerdmans, 1977), p. 267.
2 William Barclay, The Letter to the Hebrews (Philadelphia: Westminster, 1957), p. 85.
[2] R. Kent Hughes, Hebrews: An Anchor for the Soul, vol. 1, Preaching the Word (Wheaton, IL: Crossway Books, 1993), 205.
[3] Ray C. Stedman, Hebrews, The IVP New Testament Commentary Series (Westmont, IL: IVP Academic, 1992), Heb 7:20.