Tempora: Feria Tertia infra Hebdomadam XVIII post Octavam Pentecostes
Liturgical Rank: III Classis
Readings: 1 Peter 5:1–4, 5:10–11; Matthew 16:13–19
On this day the Church venerates St. Callistus, Pope and Martyr, whose pastoral courage amid persecution and doctrinal conflict mirrors the apostolic charge of St. Peter: “Feed the flock of God which is among you… being made a pattern of the flock” (1 Pet 5:2–3). The Gospel places before us the divine foundation of the papal office, when Christ says to Peter: “Thou art Peter, and upon this rock I will build My Church, and the gates of hell shall not prevail against it” (Matt 16:18).
These two passages together reveal the mystery of the Petrine office — not as a position of earthly power, but as a sacred ministry of charity, truth, and suffering. In St. Callistus, we behold one who bore that office unto martyrdom.
I. The Pastoral Charge of St. Peter
St. Peter exhorts the elders: “Feed the flock of God… not by constraint, but willingly, according to God; not for filthy lucre’s sake, but voluntarily.” (1 Pet 5:2). The shepherd’s task is both grave and tender: to guard the faithful from wolves, to nourish them with sound doctrine, and to lead them toward holiness.
St. Gregory the Great, himself a Pope after Peter, commented in his Regula Pastoralis:
“He who is set over others should surpass them in contemplation and compassion; contemplation, that he may behold the things of God; compassion, that he may bear the weaknesses of his neighbors.”
(Reg. Past. II, 5)
The true pastor must live as a bridge between God and His people. So too did St. Callistus, whose pontificate in the third century was marked by both fierce persecution and internal strife. As the Liber Pontificalis recounts, he established order among the clergy, defended the unity of the Church, and, even when accused unjustly, endured all for love of Christ and His flock.
II. “Thou Art Peter”: The Rock of Unity
In the Gospel, Our Lord asks His disciples: “Whom do men say that the Son of Man is?” (Matt 16:13). When Peter, inspired by the Father, confesses, “Thou art the Christ, the Son of the living God,” Christ answers with divine solemnity: “Thou art Peter, and upon this rock I will build My Church.”
St. Cyprian of Carthage interprets this confession as the very foundation of ecclesial unity:
“God is one, and Christ is one, and His Church is one, and the chair is one founded upon Peter by the word of the Lord.”
(De Unitate Ecclesiae, 4)
This unity, sealed in Peter and his successors, was precisely what St. Callistus guarded with his blood. Amid the schisms and moral controversies of his time, he upheld the mercy of God without compromising truth — extending penance and reconciliation even to grave sinners, a stance that provoked opposition but embodied Christ’s own heart, “who came not to call the just, but sinners.”
St. Augustine later would echo this same faith:
“For Peter, because he alone among the Apostles answered Christ, was set as the representative of the whole Church. Upon this rock, therefore, which thou hast confessed, I will build My Church; for the Rock was Christ.”
(Tract. in Joann. 124, 5)
Thus, the authority of Peter’s successors is not of man, but of Christ, perpetuating through time the visible sign of unity and the sure guide of faith.
III. The Crown of Suffering and Glory
The reading from St. Peter concludes with a promise: “After you have suffered a little, the God of all grace… will Himself perfect, confirm, and establish you” (1 Pet 5:10). The Papal office, from its first occupant to the last, bears this indelible mark of the Cross. To shepherd is to suffer — for truth, for souls, and for the unity of the Church.
St. Leo the Great, whose own papacy mirrored Peter’s firmness, declares:
“The dignity of Peter passes also to his successors; and wherever the judgment of Peter is declared, there the authority of Christ is exercised.”
(Serm. 3 de Natali ipsius)
In St. Callistus, the Church sees this dignity clothed in blood. His name, “Callistus” — “the most beautiful” — is fitting for one who reflected the beauty of charity unto death. Through his intercession, may pastors of the Church today rekindle that same apostolic zeal, and may all the faithful remain steadfast upon the Rock of Peter, trusting that the gates of hell shall not prevail.
Prayer
O God, who seest that we trust not in any deed of our own, mercifully grant that by the intercession of blessed Callistus, Thy Pope and Martyr, we may be defended against all adversities. Through our Lord Jesus Christ, Thy Son, who liveth and reigneth with Thee in the unity of the Holy Ghost, God, world without end. Amen.
Reflection
In an age when authority is often questioned and truth diluted, the feast of St. Callistus recalls the ancient and unbroken line that leads from Christ to Peter, and from Peter to every true shepherd who feeds the flock “according to God.” The Church stands still upon that rock, shining forth as a vessel of divine mercy and an instrument of unyielding truth.
“The Chief Shepherd shall appear, and ye shall receive a crown of glory that fadeth not away.” (1 Pet 5:4)