The main function of a priest in Jewish religion was offering as you see from below.
A look at the Wikipedia cite on Priesthood (ancient Israel) at the URL https://en.wikipedia.org/wiki/Priesthood_(ancient_Israel)#:~:text=The%20priests%20were%20to%20officiate,.%2C%20throughout%20the%20liturgical%20year. Can help bring into focus the traditional responsibilities of a priest in the Judeo-Christian tradition.
The priesthood was established by God, the Almighty, of which Jesus Christ is the second person of the Blessed Trinity, in Chapter 28:1,43 of Exodus in the Old Testament quoting: “Take unto thee also Aaron thy brother with his sons, from among the children of Israel, that they may minister to me in the priest’s office: Aron, Nadah, and Abiu, Eleazar and Ithamar. . . And Aaron and his sons shall use them when they shall go in to the tabernacle of the testimony, or when they approach in the altar to minister in the sanctuary, lest being guilty of iniquity they die. It shall be a law for ever to Aaron, and to his seed after him.”
Jeremiah 31:31 “Behold the days shall come, saith the Lord, and I will make a new covenant with the house of Israel, and with the house of Judah.”
The New Covenant Matthew 28:18-20 “And Jesus coming spoke to them saying: All power is given me in heaven and in earth. Going therefore. Teach ye all nations, baptizing them in the name of the father and of the son and of the Holy Ghost. Teaching them to observe all things whatsoever I have commanded you and behold I am with you even to the consummation of the world.”
Above it says “it shall be a law for ever to Aaron, and to his seed after him.” But in time, since it reads “for ever” not in the timelessness of eternity, anyway, all power in heaven and earth was given to Jesus Christ, it being within his power to alter, so that there is no doubt that He can alter it though by technicality of eternity and heaven he does not need to alter it. All of Aarons decedents power stops in this world before the door of the next world where Jesus now rules, given all power by his Father. It would be, in my opinion, absurd if Aaron, the high priest of Isreal at the time, had “seed” and the king of heaven and earth, that is the cosmos, did not. Aaron is a “type” of Jesus Christ and him and his decedents are the priests of the Old Testament. So that gentiles could also be selected as priest, a supernatural, as opposed to a natural form of selection (i.e. priests selected through their blood line, lineage from Aaron) was created by Jesus Christ. God chooses his priests, and we know He selects them through his apostles because of Acts 1:20-26.
For it is written in the book of Psalms: Let their habitation become desolate, and let there be none to dwell therein. And his bishopric let another take.
21Wherefore of these men who have companied with us, all the time that the Lord Jesus came in and went out among us, 22Beginning from the baptism of John, until the day wherein he was taken up from us, one of these must be made a witness with us of his resurrection. 23And they appointed two, Joseph, called Barsabas, who was surnamed Justus, and Matthias. 24And praying, they said: Thou, Lord, who knowest the heart of all men, shew whether of these two thou hast chosen, 25To take the place of this ministry and apostleship, from which Judas hath by transgression fallen, that he might go to his own place. 26And they gave them lot, and the lot fell upon Matthias, and he was numbered with the eleven apostles.
The psalm reference is from Psalm 109:8 in your bible but Psalm 108:8 in Douey-Rheims because of psalm enumeration idiosyncrasies between some protestant and some catholic bibles.
Priests cannot select themselves and ministers of the protestant religion are not the same as priest since the main functions of a priest is making offerings and more precisely making sacrifices (see Wikipedia cite on Priesthood (ancient Israel)) and protestant preachers/ministers preach, they do not consecrate the Eucharist and in union with Jesus Christ the high priest re-offer the sacrifice of calvary for the propitiation of sins to empower the efficacy of confession, the one sacrifice which all others throughout time were types of. Only Jesus Christ’s sacrifice has merit and only consecrated Hosts, by priests, who are selected supernaturally, which his why that verse from acts is included in the New Testament, can validly consecrate and offer the Holy Sacrifice of the Mass which is the self-same sacrifice offered on Calvary. This sacrifice is what gives the priest in the catholic religion, as mentioned earlier, the power to forgive sins in confession also called the sacrament of penance.
Information here is from URL https://www.drbo.org/chapter/65008.htm
1- Now of the things which we have spoken, this is the sum: We have such an high priest, who is set on the right hand of the throne of majesty in the heavens [Hebrews 8:1] 2 A minister of the holies, and of the true tabernacle, which the Lord hath pitched, and not man. 3 For every high priest is appointed to offer gifts and sacrifices: wherefore it is necessary that he also should have some thing to offer. 4 If then he were on earth, he would not be a priest: seeing that there would be others to offer gifts according to the law, 5 Who serve unto the example and shadow of heavenly things. As it was answered to Moses, when he was to finish the tabernacle: See (saith he) that thou make all things according to the pattern which was shewn thee on the mount.
[2] “The holies”: That is, the sanctuary.
[4] “If then he were on earth”: That is, if he were not of a higher condition than the Levitical order of earthly priests, and had not another kind of sacrifice to offer, he should be excluded by them from the priesthood, and its functions, which by the law were appropriated to their tribe.
[5] “Who serve unto”: The priesthood of the law and its functions were a kind of an example and shadow of what is done by Christ in his church militant and triumphant, of which the tabernacle was a pattern.
6 But now he hath obtained a better ministry, by how much also he is a mediator of a better testament, which is established on better promises. 7 For if that former had been faultless, there should not indeed a place have been sought for a second. 8 For finding fault with them, he saith: Behold, the days shall come, saith the Lord: and I will perfect unto the house of Israel, and unto the house of Juda, a new testament: 9 Not according to the testament which I made to their fathers, on the day when I took them by the hand to lead them out of the land of Egypt: because they continued not in my testament: and I regarded them not, saith the Lord. 10 For this is the testament which I will make to the house of Israel after those days, saith the Lord: I will give my laws into their mind, and in their heart will I write them: and I will be their God, and they shall be my people:
11 And they shall not teach every man his neighbour and every man his brother, saying, Know the Lord: for all shall know me from the least to the greatest of them: 12 Because I will be merciful to their iniquities, and their sins I will remember no more. 13 Now in saying a new, he hath made the former old. And that which decayeth and groweth old, is near its end.
[11] “They shall not teach”: So great shall be light and grace of the new testament, that it shall not be necessary to inculcate to the faithful the belief and knowledge of the true God, for they shall all know him.
[13] “A new”: Supply ‘covenant
The house of Juda is the house of David and Jesus Christ by the flesh is decedent from him not of the Levitical line of Aaron. He is a priest and king in the order of Melchizedek (Genesis 14:18 who was also a priest and a king) who offered bread and wine, as in the Catholic Eucharist, which Jesus chose to convert to his actual body and blood during the consecration at mass. The Eucharist or communion at a catholic mass is a true sacrifice of Christs body, which by tradition is always performed by a priest, as related in John 6:51-72. Basically, he said and did not take it back, If you don’t believe I can actually change bread and wine into my body and blood you can leave, because you evidently will not actually be able to believe I am God.
Jesus morphed the traditional Aaronic Priesthood to the Catholic priesthood we have today to offer the sacrifice of Calvary in the daily mass so that the prophesy in Malachias (Malachi 1:11) may be fulfilled: “For from the rising of the sun even to the going down, my name is great among the Gentiles, and in every place there is sacrifice, and there is offered to my name a clean oblation: for my name is great among the Gentiles, saith the Lord of hosts.”
But this is all well and good but why can’t the Holy Ghost communicate directly? The answer is of course He can but just as Adam and Eve were the test for all men and the origin of original sin, Jesus that is God prefers to work through his church and that is why tradition and the teaching of one generation to another is important and why Peter is so important.
Luke 24:12-36 from the same Doua-Rheims web site shown above.
12 But Peter rising up, ran to the sepulchre, and stooping down, he saw the linen cloths laid by themselves; and went away wondering in himself at that which was come to pass. 13 And behold, two of them went, the same day, to a town which was sixty furlongs from Jerusalem, named Emmaus. 14 And they talked together of all these things which had happened. 15 And it came to pass, that while they talked and reasoned with themselves, Jesus himself also drawing near, went with them.
16 But their eyes were held, that they should not know him. 17 And he said to them: What are these discourses that you hold one with another as you walk, and are sad? 18 And the one of them, whose name was Cleophas, answering, said to him: Art thou only a stranger to Jerusalem, and hast not known the things that have been done there in these days? 19 To whom he said: What things? And they said: Concerning Jesus of Nazareth, who was a prophet, mighty in work and word before God and all the people; 20 And how our chief priests and princes delivered him to be condemned to death, and crucified him.
21 But we hoped, that it was he that should have redeemed Israel: and now besides all this, today is the third day since these things were done. 22 Yea and certain women also of our company affrighted us, who before it was light, were at the sepulchre, 23 And not finding his body, came, saying, that they had also seen a vision of angels, who say that he is alive. 24 And some of our people went to the sepulchre, and found it so as the women had said, but him they found not. 25 Then he said to them: O foolish, and slow of heart to believe in all things which the prophets have spoken.
26 Ought not Christ to have suffered these things, and so to enter into his glory? 27 And beginning at Moses and all the prophets, he expounded to them in all the scriptures, the things that were concerning him. 28 And they drew nigh to the town, whither they were going: and he made as though he would go farther. 29 But they constrained him; saying: Stay with us, because it is towards evening, and the day is now far spent. And he went in with them. 30 And it came to pass, whilst he was at table with them, he took bread, and blessed, and brake, and gave to them.
31 And their eyes were opened, and they knew him: and he vanished out of their sight. 32 And they said one to the other: Was not our heart burning within us, whilst he spoke in this way, and opened to us the scriptures? 33 And rising up, the same hour, they went back to Jerusalem: and they found the eleven gathered together, and those that were staying with them, 34 Saying: The Lord is risen indeed, and hath appeared to Simon. 35 And they told what things were done in the way; and how they knew him in the breaking of the bread.
36 Now whilst they were speaking these things, Jesus stood in the midst of them, and saith to them: Peace be to you; it is I, fear not.
So it is implied, and I know you will come up with some explanation like it does not clearly say Peter was one of the two going to Emmaus, it is not a bad assumption that he was since he was mentioned in the previous sentence. During this walk it is said in this excerpt that Jesus Christ: ” . . . beginning at Moses and all the prophets, he expounded to them in all the scriptures, the things that were concerning him. And they drew nigh to the town, whither they were going: and he made as though he would go farther. But they constrained him: saying: Stay with us, because it is towards evening, and the day is now far spent. And He went in with them. And it came to pass, whilst he was at table with them, he took bread, and blessed, and brake, and gave to them. And their eyes were opened, and they knew him: . . .”
So how did the early church filled with illiterate men, find all the passages concerning Christ with out the tradition from these men, possibly one being Peter? I think you would agree the cite from Malachi above is rather vague, to say the least, concerning the sacrifice of the mass.
A line from Acts 8:26-35, shows one ignorant of the gospel, with Philip asking him “Thinkest thou that thou understandest what thou readest? Who said: And how can I, unless some man shew me? And he desired Philip that he would come up and sit with him. . . Then Philip, opening his mouth, and beginning at this scripture, preached unto him Jesus.” Philip might have been one of the 12 apostles. You may agree or disagree, but this, to me, shows, that to actually understand the New Testament, someone that was taught the meaning from Christ’s apostles, or one who was taught by one of his apostles’ priests or bishops etc. is needed to get the correct interpretation. The fact that there are on one books count over 40,000 separate protestant denominations, all with different interpretations, speaks to the fact that the Holy Ghost is not speaking to each of them otherwise their interpretation would be universally the same. That is why there is ONE CHURCH, to ensure the interpretation is uniform and correct, the requirement being to insure everyone is uniformly charitable in heaven and unconditionally love the true God, love him enough to join his church in spite of any pride they might have had at being born non-Catholic. This would also lead to the human involved to being not happy and every one in heaven is totally happy with God there, with this being the ultimate goal of their life.
Traditional Thomistic Catholic 