Priesthood, like marriage, goes all the way back to the beginning (Mk. 10:6). Most theologians have supposed that even had human beings remained unfallen, they would still have been obliged to offer sacrifices of adoration and thanksgiving to God. Sacrifice is a matter of natural law, St. Thomas Aquinas tells us. But priesthood and sacrifice go together, as much as a painter and a painting. You can’t have one without the other.
Doubtless, our first father was intended to be high priest of creation, just as he was to be its king. Perhaps he retained both offices even after the Fall. Yet Scripture nowhere speaks of Adam as offering sacrifice. He was to prefigure mankind in need of redemption: it would have been confusing if the Bible had presented him also as a prefigurement of the Redeemer. Instead, it is his first two sons, Abel and Cain, who are first found sacrificing. The sacrifice of Cain, who offered only “fruits of the earth”—and not necessarily first-fruits, either—was rejected. Abel had the faith to perceive that without blood there is no remission of sin (Heb. 9:22); he thus merited to become the first martyr-priest, and he continues to be remembered at the altar whenever a Catholic priest recites the Roman canon.
How were priests designated, in the most ancient times? St. Jerome and others tell us that until the giving of the Law to Moses, it was generally the first-born son of each family who had the right to offer sacrifice to God. In that simple manner was verified in those days the principle later recalled by St. Paul, that no man takes the honor of the priesthood to himself (Heb. 5:4). Nobody can decide to be a first-born son. But God was also foreshadowing the day when another first-born Son would become a priest.
It was to those patriarchal times, before the call of Moses, that the mysterious Melchisedech belonged. Who was he? St. Ephraim the Syrian, a doctor of the Church, thinks that he was Shem, the son of Noah, and that it was he whom Rebecca went to consult when she was suffering in her pregnancy from the twins who tussled inside her (Gen. 25:21). The fact that Abraham himself did him homage shows that Melchisedech was greater than all the Jewish high-priests to come. This is one reason why our Lord would later be called a priest of the order of Melchisedech.
When He gave the Law to Moses, God made a change in the priesthood. No longer would it be all the first-born sons who would have the right and duty of offering sacrifice, but only the male descendants of Aaron, Moses’s brother. This was perhaps partly a punishment for the affair of the golden calf, where Aaron’s tribe were more faithful than the others. But it was also done in order that, in due time, Christ’s priesthood would appear in all its newness. For He was not a descendant of Aaron, nor did He even come from Aaron’s tribe.
“When the fullness of time was come,” writes St. Paul, “God sent his Son, made of a woman,” made a priest. At what moment did this unique priestly ordination occur? At the incarnation itself. Although theologians discuss the finer details, all of them agree that the second Person of the Blessed Trinity, by taking to Himself a human nature, became our Priest.
Yet it is as man, rather than as God, that Jesus is a priest. A priest is by definition a kind of mediator between two parties. In His divine nature, Christ is perfectly equal to the Father, not a mediator and intercessor with Him. It is in His human nature that He was “anointed” with the Holy Spirit: filled with all the graces and virtues by which He would offer Himself as a ransom for many.
When, I wonder, did the disciples first begin to think of their Master in this way? During His public ministry, He showed Himself, rather, as teacher, exorcist, and thaumaturge. He deferred to the existing hierarchy, sending lepers to have their cures verified by the Jewish priests, as the Law required. He speaks divinely excoriating words against scribes and Pharisees, but we never find Him rebuke a priest as such, not even Caiaphas, who declared Him worthy of death. Perhaps it was not until the Last Supper, when “He took bread into His holy and venerable hands” that the minds of the apostles were enlightened to see that their Master was also the priest foretold in the book of Psalms (Ps. 109:4).
Our Lord offered the first Mass on that occasion, and ordained the Twelve as His ministers. After all, He could hardly be a high-priest, as St. Paul insists He is, unless there were other, lesser priests beneath Him. Christ also foresaw, as He consecrated the Bread and the Chalice for the first time, all the sacrifices that His ministers would offer until the end of the world. He willed that whenever a duly ordained priest pronounced the sacred words, the substance of the bread and wine would be converted into the substance of His body and blood. In His humility and magnanimity, He willed this even while foreseeing that some of His ministers would use their power unworthily.
There was so much to think about on that great and terrible night, that the apostles could hardly have realized that they had just witnessed the change from the old to the new priesthood. And which of them, next day, was able to see that the Crucifixion, though the act of greatest injustice on the part of those who perpetrated it, was, on His side, the supreme priestly act, reconciling heaven and earth, and gaining all the graces that would be bestowed on mankind through the sacrifices and sacraments of the Church? Perhaps St. John, at least, perceived something of this, remaining as he did by the side of our Lady.
But it must have been after the resurrection, during those forty days when He was speaking of the kingdom of God (Acts 1:3), that Christ explained to the apostles how they were to do what He had done in the cenacle, and become dispensers of the mysteries of God (I Cor. 4:1), the sacraments of grace. Nor is the liturgy of the Church exhausted by the Mass and the sacraments. It contains also the hours of the divine office, which whether sung in choir, in Gregorian or Byzantine or Coptic chant, or recited sotto voce by a cleric in his private chapel, or even if need be in a bus or train, form part of the Church’s public prayer. In the first century, Pope St. Clement I reminded the Corinthians that the liturgy is not a human invention, but goes back to Christ Himself: “He commanded us to celebrate sacrifices and services, and that it should not be done thoughtlessly or disorderly, but at fixed times and hours” (First Letter of St. Clement, 40).
Now that our Saviour has ascended, He is still acting as high-priest. It was fitting, says St. Paul, that we should have a high priest separated from sinners, and made higher than the heavens (Heb. 7:26). It was fitting, because what He obtains for us by His priesthood is holiness and eternal life. Yet though He is separated from us sinners, as glory is from mortality, He is not distant from us. A priest who says Mass, or forgives sins, or anoints a sick or dying man, is not simply acting in virtue of the mandate which Christ gave to the apostles long ago. Christ acts through him here-and-now, using him as an instrument, just as the painter uses his brush. “When you see the priest make the offering,” St. John Chrysostom told his flock in Constantinople, “do not think about the man who does this, but see instead the hand of Christ invisibly stretched forth” (Homily 83 on St. Matthew).
More than this, Jesus is always living to make intercession for us (Heb. 7:34). He expresses to His Father the holy desire of His soul for our salvation. It is an unimaginable prayer, as the life of heaven must be for us wayfarers. The five sacred Wounds that He retained after the resurrection are the outward signs of its eloquence and power. It is in virtue of this prayer that our own prayers to the Father can be acceptable, and, especially, that the liturgy of the Church possesses its hidden power to turn back the advance of evil on the earth.
The Mass and the sacraments will come to an end one day, when Christ returns. Yet He will be a high-priest forever, and through Him the blessed will perpetually offer their sacrifice of praise, adoration and thanksgiving. As St. Augustine put it: “There we shall rest and see, see and love, love and praise. This is what shall be in the end without end.”