John Chrysostom

Having passed on from the fornicator to the covetous person, he comes back to the former from the latter, no longer henceforth discoursing with him but with the others who had not committed fornication. And in the act of securing them lest they fall into the same sins, he assails him again. For he that has committed sin, though you direct your words to another, is stung even in that way; his conscience being thoroughly awakened and scourging him. Now the fear of punishment indeed was enough to keep them in chastity. …

Homily on 1 Corinthians 18 ↗

Theophylact of Ohrid

Again he returns to the previously proposed exhortation concerning fornication. Meanwhile, he arms his discourse with great terrors. He did not say: to unite with a harlot, but, what is more terrible, "to make them members of a harlot." Indeed, who would not be horrified, hearing these words, that is, to tear away the members from Christ and make them members of a harlot?

Commentary on 1 Corinthians ↗

Cyprian

Christ gave this judgment when, being inquired of, He said that a wife must not be put away, save for the cause of adultery; such honour did He put upon chastity. Hence arose the decree: "Ye shall not suffer adulteresses to live."8 Hence the apostle says: "This is the will of God, that ye abstain from fornication."9 Hence also he says the same thing: "That the members of Christ must not be joined with the members of an harlot."10 Hence the man is delivered over unto Satan for the destruction of the flesh, who, treading under foot the …

Pseudo-Cyprian Of the Discipline and Advantage of Chastity ↗

Thomas Aquinas

Then when he says, Do you not know, he presents a second reason, which is taken from the human body's affinity to Christ, namely: the fornicating man's members are the prostitute's members, but a man's members are Christ's members. Therefore, by fornicating, Christ's members become the prostitute's members, which is unbecoming. In regard to this he does four things: first, he presents the major, saying: Do you not know that your bodies are members of Christ? …

Commentary on 1 Corinthians ↗

Bonaventure

To approach Christ is through faith, or through the Sacrament of faith; and the faith of Christ is the same in past, present, and future: therefore the ground of influencing is posited in Christ with respect to all, past as well as present as well as future, who believe in Christ and are reborn in Christ, who through faith are joined to Christ and through inflowing grace become members of Christ and temples of the Holy Spirit, and thereby children of God the Father, connected to one another through the indivisible bond of charity. …

Breviloquium ↗