I’m still perplexed by D&C 84:39 and what exactly this oath & covenant is. The language is so wonderfully elusive. It simply says that what comes before it is “according to” this oath and covenant, and then that this oath and covenant “belongs” to the priesthood.
In my latest reflections on this verse, I’ve been thinking through Hebrew’s assertion that the Aaronic priesthood does not need to be received with an oath and the Melchizedek priesthood does. If that is the case, then I think the language of “belonging” to the priesthood probably means that an oath & covenant is associated or belongs or is necessary for the Melchizedek priesthood. (That would also mean that “priesthood” here means Melchizedek priesthood.)
What I’ve gathered from the Hebrews Interpretation commentary is that that author is setting up a comparison between Christ as a Melchizedek figure and the current temple priesthood as Aaronic/Levitical. The Aaronic priesthood performs outward rituals that aren’t lasting (they need to be repeated) and their priesthood doesn’t go with them into the grave. But Christ, as a Melchizedek figure, performs rituals that are lasting (that only need to be performed once) and His priesthood does extend past the grave. The reason that last point is important is because when we extend past the grave, He is there as our priest to guide us back to the Father Himself.
The Interpretation commentary isn’t, of course, thinking of Melchizedek priesthood as a Mormon would. We don’t think of Christ and Melchizedek as uniquely holding the Melchizedek priesthood. The commentary gives the sense that Christ, as eternally holding the priesthood, was the last priest necessary. If He still holds it and officiates for us, why would any new priests be necessary? That’s what happens in the Aaronic priesthood, not the Melchizedek.
So, I’ve got to work around that idea when I read D&C 84. I think the section agrees with a lot of what the book of Hebrews says about Aaronic versus Melchizedek priesthood. Except, that Moses and others also had the Melchizedek priesthood. And, also, that they “sought diligently” to use that authority to bring their people into the presence of God while on earth, and not only when they passed beyond into the heavens.
When those are combined, what do we make of D&C 84:39? The previous verses talk about coming into the presence of God and receiving what God has. This sounds similar to what Hebrews says Christ can do because He is a high priest forever. (Because He is still our priest after death, He can take us to God Himself in the true temple — that is, in Heaven.) If that idea is what D&C 84 has in mind, then this idea is being applied to any person with Melchizedek priesthood. Those who receive God’s servants who have this priesthood can also enter into God’s presence. And this promise is according to oath & covenant of the priesthood, which promises this priesthood will last forever.