In the series “10 reasons why Melchizedek was actually the pre-incarnate Word of God” the following article is reason # 10.
It is witnessed that Melchizedek lives forever.
According to Hebrews 7:8:
And here [on earth] men that die receive tithes; but there [in heaven] he [Melchizedek] receiveth them, of whom it is witnessed that he liveth.
In Hebrews 7:8, the counter-phrase “he liveth” must mean that Melchizedek has and will live forever because it is the direct contrast to the initial phrase “men that die.” But where in the bible exists a witness that Melchizedek cannot die? The answer is found in Psalms 110:4 which the writer of Hebrews quotes no less than 5 times (Hebrews 5:6; 5:10; 6:20; 7:11; 7:17; 7:21). In Psalms 110:4, God declares that Christ—and not Melchizedek—is a high priest for ever. Notwithstanding, the good and necessary consequence of Psalms 110:4 is that Melchizedek must also be a high priest forever since Christ’s designation as a perpetual high priest is predicated upon a trait of Melchizedek’s order (Hebrews 7:17). To illustrate this point further, If God, speaking of Caiaphas were to say “you’re going to be a high priest until the day you die, after the order of Levi” this would tell us that in the Levitical priesthood, high priest are “not [allowed] to continue by reason of death.” (Hebrews 7:23). This is understood because the trait of a temporary high-priesthood which God attributes to Caiaphas is derived from the order of Levi. Likewise, when God in Psalms 110:4 declares that Christ is a high priest forever after the order of Melchizedek, this tells us that in the Melchizedek priesthood, high priests hold their position perpetually. But again, we can’t have both Christ and Melchizedek being perpetual high priests at the same time so this discovery can only mean that Christ and Melchizedek are the same person. If this conclusion sounds similar to another one that we have encountered in the past, it’s because the proposition that “Melchizedek lives forever” is a necessary implication of him “abiding a priest continually” which we discussed in Reason 6.
Regarding Hebrews 7:8, Dr. Henry Morris states:
This “witness” was in Psalms 110:4, where the coming Messiah was recognized by God as “a high priest for ever after the order of Melchizedec.” There could be only one such high priest forever! The King of Righteousness (meaning of “Melchizedec”) who blessed Abraham is also our eternal High Priest, the “one Mediator between God and men, the man Christ Jesus” (1Timothy 2:5).