We might imagine that, Jesus’ closest disciples had figured out Jesus’ identity before they began to follow Him. That wasn’t the case.

This Sunday’s Gospel, Matthew 16:13-20, is the turning point in the Gospel of Matthew. Jesus asks the disciples: “Who do you say I am?” (Mt 16:15). Peter, as the spokesman for the disciples, declares: “You are the Christ (Messiah), the Son of the living God” (Mt 16:16).

The Gospels make it clear that Jesus only gradually revealed His identity even to His disciples. The last sentence of this passage states that Jesus “strictly ordered His disciples not to tell anyone that He was the Messiah (Mt 16:20).

Since Matthew’s Gospel had twenty-eight chapters, this passage is coming half way through the Gospel. Mark (8:29) and Luke (9:20) also place this passage midway in their Gospels.

Slowly by slowly, step by step, Jesus led the disciples to a deeper understanding.

Just as teachers pose questions to help their students articulate what they understand, so does Jesus. St. Thomas Aquinas recalls St. Jerome’s words “When the wise man asks a question, he teaches.”

According to Thomas, Peter’s confession touches on both the humanity and the divinity of Christ. St. Thomas declares that Peter’s faith is “perfect … because his faith in Christ’s humanity is included” (Commentary on the Gospel of Matthew). We might think that believing in Jesus’ humanity is easier because it is more evident than the humanity. In fact, however, there have been Christians who have so emphasized the divinity of Christ as to diminish His humanity.

Christus is the Greek for Messiah, the one who is “anointed.” Peter recognizes that Jesus, in His humanity, is “the anointed one.”

How is Jesus anointed? Jesus declares that He is anointed with the Spirit. When Luke recounts Jesus words in the Synagogue of Nazareth, he tells us that Jesus applied the words of Isaiah to Himself: “The Spirit of the Lord is upon me, because He has anointed Me to preach the gospel to the poor…” (Isaiah 61:1).

This anointing is associated with His baptism, “He saw the Spirit of God descending like a dove and coming upon Him” (Mt 3:16). The Acts of the Apostles describes Jesus as “the Lord’s anointed” (Acts 4:26).

In Mark’s and Luke’s Gospels, the disciples simply profess, “You are the Christ (“Messiah”).” Matthew reports that Peter recognizes Jesus not only as the “Christ” but also as the “Son of the Living God.”

Thomas Aquinas asserts: “Peter not only confessed His humanity, but having penetrated the shell, he rises above it all the way to His divinity” (Commentary on the Gospel of Matthew).

Jesus responds to Peter’s profession: “Blest are you, Simon son of John! No mere man has revealed this to you but My Father in heaven” (Mt 16:17).

All faith is moved by a revelation by God, as Thomas comments: “Faith, as regards the assent which is the chief act of faith, is from God moving a person inwardly by grace” (Summa Theologiae, 2a.2ae. 6, 1).

Many of us also have grown slowly in our appreciation of Jesus’ identity. It is true that from our childhood we have known that Jesus has a divine and human nature but to realize the implications of Jesus’ action upon us in His divine and human natures is a slow process. Each step is a grace as it was with Peter. St. Thomas reflects, “… His confession could only be made by the Holy Spirit” (Commentary on the Gospel of Matthew).

Jesus declares that Simon is “Peter,” the “rock” on which He will build His Church. The Greek, petra, means “rock.” Thomas reflects that a rock gives firmness to a foundation. Earlier in the Gospel, Jesus had announced that “a wise man builds his house on rock” (Mt 7:24).

Paul speaks of Christ as the “foundation”: “No one can lay a foundation other than that one that is there, namely, Jesus Christ” (1 Cor 3:11). Thomas asks whether Christ can be the foundation or Peter and the disciples can be the foundation? He explains: “Christ, in and of Himself, is the foundation, but through Christ’s delegation and the authority given them by Christ, they are foundations as well” (Commentary on the Gospel of Matthew).

The Letter to the Ephesians declares that believers are “built upon the foundation of the apostles and prophets, with Christ Jesus Himself as the capstone” (Eph 2:20).

The Book of Revelation likewise proclaims: “The walks of the city had twelve courses of stones as its foundation, on which were inscribed the twelve names of the twelve apostles of the Lamb” (Rev 21:21).

Thomas emphasizes that Peter’s role on which the Church is built rests upon the “faith of Peter.” Thomas insists that Peter’s faith is important for the Church. He recalls Jesus’ words to Peter at the Last Supper: “I have prayed that your faith may not fail but when you have turned, strengthen your brothers” (Lk 22:32).

We might forget that our faith has been handed on to us by others just as we hand faith on to others. Peter’s role among the apostles is clear. Catholics believe that bishops continue to take the role of the apostles and the pope takes the role of Peter in the Church. Thomas especially calls attention to “the faith of Peter” (Commentary on the Gospel of Matthew). The faith of the pope, as Thomas says, in “the place of St. Peter,” in a special way gives firmness to our own faith.

Jesus announces to Peter: “I will entrust to you the keys of the kingdom of heaven. Whatever you declare bound on earth shall be bound in heaven; whatever you declare loosed on earth shall be loosed in heaven” (Mt 16:19).

Many Christians accept Christ but find it difficult to accept human intermediaries, especially as instruments of God’s forgiveness. Thomas interprets Jesus’ giving the keys of heaven and the authority to bind and loose in terms of the Sacrament of Reconciliation. In John’s Gospel, the Risen Jesus declares to His disciples gathered in the upper room on Easter evening: “Receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained” (Jn 20:22-23).

According to Thomas, the impediment to our entering the kingdom of heaven lies not in the kingdom itself but in our sins. This impediment was removed, in principle, through Jesus’ Passion. Thomas recalls the words of the Book of Revelation: “To Him who loves us and has freed us from our sins by His blood” (Rev 1:5).

Thomas notes that, in Jesus’ words, “I will give you the keys,” there is an indication that the giving of the keys would take place in the future. Thomas explains that the time of the “keys” came after Jesus’ death and resurrection, “He made known the efficacy of this sacrament and the source of its power… after speaking of His Passion and Resurrection. Because it is from the power of the name of Jesus Christ suffering and rising again that this sacrament is efficacious for the remission of sin” (Summa Theologiae, 3a. 84, 7).

When explaining the removal of sin in Baptism and in Reconciliation, Thomas affirms that “the sacraments of the new law give grace” and “the sacraments of the new law effect what they signify.” In other words, the sacraments bring about what they symbolize.

According to Thomas, the sacraments of baptism and Reconciliation “have an “instrumental spiritual power” to “cleanse a person from guilt” (Commentary on the Gospel of Matthew). Christ continues to act through the sacraments as His instruments.

Thomas explains that the priest is called a “minister” of the sacrament because he is given an “instrumental spiritual power … as a minister, he administers the forgiveness of sin, as in the water of Baptism.” Thomas recalls that, in the sacrament of reconciliation, the priest says “I absolve you,” just as, in baptism, the priest says “I baptize you.” Of course, the forgiveness comes from God not himself. His role in the sacrament is one of cooperation with grace.

As an indication that the forgiveness comes from God, Thomas explains that to confess one’s sins as an action of conversion “requires grace.” “It is grace that takes away sin.” If an adult is not contrite, the effect of the sacrament, the remission of sin, does not take place.

It can happen that a person approaches the sacrament without being totally contrite. Thomas thinks that it is possible that, by the power of the grace received in the sacrament, the person may come to perfect contrition.

Thomas insists that the priest is “the minister of God” and “the action of the minister depends on the action of God… the priest acts ministerially but God pours out grace.”

Denis Vincent Wiseman, O.P.

References to St. Thomas Aquinas’ Commentary on the Gospel of St. Matthew are taken from the translation of Fr. Paul M. Kimball, published by Dolorosa Press in 2012, pp. 341-345.

References to St. Thomas Aquinas’ Summa Theologiae give the part of the Summa, followed by the particular question, then the particular article. If the quotation is from the reply to an objection, the objection is indicated with the Latin ad (to).