Hebrews 5:4-6
4 No man takes this honor for himself, but he who is called by God receives it, just as Aaron did.
5 So also Christ did not glorify Himself to be made a High Priest, but it was He who said to Him:
“You are My Son;
today I have become Your Father.”[a]
6 As He also says in another place:
“You are a priest forever
in the order of Melchizedek.”[b]
a Hebrews 5:5 Ps 2:7.
b Hebrews 5:6 Ps 110:4.
The writer of Hebrews shows us that the Priesthood of Jesus has made the priesthood descended from Aaron obsolete, superceded by the ultimate perfection of Jesus’ sacrifice. This Scripture is important for what it says, of course, but I'm citing it at this point for what it doesn't say.
There is another priesthood which has become very prevalent in society. It is the priesthood to which movies and TV resort whenever they want to depict Christianity in popular culture. But it is a priesthood after neither Aaron nor Melchizedek.
In my recent interactions with this belief system on social media, I find that the respondents counter any attempt to cite Scripture that contradicts their claims with references to "church fathers" or "important Catholic writers". Some even sneer at attempts to make them subject to anything God actually said or did. No, the Mary of the Catholic church and related denominations is not the simple peasant girl blessed by God, but an pagan derivative—an idol (Juno?). Purgatory, from which the dead must be promoted by repetitive prayer, is a man-made fantasy. As Jesus said, “Today you will be with Me in Paradise” (Luke 23:43). But such conversation is always vigorously steered away from Scripture toward those other writings.
I have been called "philosemetic"--which I didn't know was a word--for suggesting that the Hebrew Bible (what Christians call the Old Testament) was written down by the Hebrews (later reduced to Judah and remnants of Benjamin), rather than ancient Catholics. There are claims, as far as I can decipher them, that the modern releases of the Leningrad Codex of the Hebrew Bible are the entirety of our Biblical textual history, and that the Bible Christians read is our modern, 20th Century, heretical attempt to rebel against the “real” writings of some ancient proto-Catholics.
2 Corinthians 10:5
5 We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ.
The priesthood of Roman Catholicism must reject and dismiss references to God's actual Word, because it isn't in there. I'll go further, and argue that it is the old Greco-Roman polytheism, rebadged with Christian names, a "pretension that sets itself up against the knowledge of God".
Matthew 15:9
9 In vain they do worship Me,
teaching as doctrines the precepts of men.[c]
c Isa 29:13.
If you have been part of this belief system, I plead with you, urgently and lovingly, to escape at your first opportunity from this body of death. Stop being a slave to mere rules made up by men.
Faith in Jesus Christ alone will save you. No man should ever be allowed to place himself between God’s Love and His people. Learn what Jesus and the apostles and teachers of the New Testament really said and did, and cling to those things in the instruction and guidance of the Holy Spirit.
26 But the Counselor, the Holy Spirit, whom the Father will send in My name, will teach you everything and remind you of all that I told you.