I recently answered the following Calvinist objection to the Catholic Priesthood:
The simple facts are: The Catholics claim that word presbyteros means that there is the general priesthood of the laity and the sacrificial priesthood of the Church hierarchy. No, AND I MEAN NO, credible linguist understands this word to have two meanings; hence bimodal. This is a major, major problem.My answer:
The word Presbyteros means "elder" or "old man". In the Old Covenant it often referred to officials in the synagogue or the esteemed elder members of the Jewish community.
In itself, it has no specific "priestly" connotations, other than that the "elders" of synagogues often led worship which is kind of ministerial or priestly, though they didn't offer sacrifice, which is what is essence of being a "priest" or "hieros".
But one makes a mistake about "presbyteroi" not being "priestly" or "sacerdotal." He needs to look to the book of Revelation. There we see the 24 "presbyteroi" assembled around the altar of the slain and risen Lamb of God offering incense and dressed in Jewish priest's vestments. The number 24 signifies the 24 divisions of the Old Covenant priesthood. (The Aaronic priesthood was divvied up into 24 divisions.)
Thus the New Testament elders have taken on priestly function in heaven and on earth. Presbyters of the ecclesia or elders and sacerdotal priests.
Catholicism teaches that there is really only ONE priest when it comes down to it and that is Jesus Christ. One may participate in His Priesthood in two modes. The first is through baptism and confirmation. This participation is called the "General Priesthood" or as Protestants say, "Priesthood of Believers."
The second way is through the "Ministerial Priesthood." This is through the Presbyterate (or Episcopate). St Paul speaks of this "priesthood" or "hieros" in the book of Romans of all places. He refers to his clerical ministry as a priestly, using the Old Testament word for priest:
Romans 15:16 "to be a minister of Christ Jesus to the Gentiles in the ***priestly service*** of the gospel of God, so that the offering of the Gentiles may be acceptable, sanctified by the Holy Spirit."
Thus, the clerical ministry is a "priestly service" distinct from the baptismal priesthood of the believers.
1. There is Christ the one Great High Priest.
2. We participate in His Priesthood (that of Melchizedek) through baptism and confirmation.
3. Some of the baptized participate in the ministerial functions of Christ through the ministerial priesthood - i.e. the Catholic priesthood.
One should be reminded that Melchizedek "offered bread and wine" as a priest and this is what Christ did. But by telling the 12 Apostles, "Do this in memory of me," he extended this Melchizedecian priesthood function to the Apostles and by extension the Catholic priests in Apostolic Succession.
Calvinists need to ask themselves, "If Presbyters in the book of Revelation (and hence currently in Heaven) are wearing vestments, kneeling, chanting, and offering incense around the Altar, why don't their "Elders" do the same?"
The answer is that they are lacking the full understanding of Sacred Scripture and the teaching of the Catholic Church. St John the author of Revelation knew Presbyters to be priestly, because he observed this reality in Heaven on the Lord's Day.