Luke 24:47

For it was said, Ask of me, and I will give thee the heathen for thine inheritance. (Ps. 2:8.) But it was necessary that those who were converted from the Gentiles should be purged from a certain stain and defilement through His virtue, being as it were corrupted by the evil of the worship of devils, and as lately converted from an abominable and unchaste life. And therefore He says that it behoves that first repentance should be preached, but next, remission of sins, to all nations. For to those who first showed repentance for their sins, by His saving grace He granted pardon of their transgression, for whom also He endured death.

(Hom. i. in Act.) Further, lest any should say that abandoning their acquaintances they went to show themselves, (or as it were to vaunt themselves with a kind of pomp,) to strangers, therefore first among the very murderers themselves are the signs of the resurrection displayed, in that very city wherein the frantic outrage burst forth. For where the crucifiers themselves are seen to believe, there the resurrection is most of all demonstrated.

Not only because to them were entrusted the oracles of God, and theirs is the adoption and the glory, but also that the Gentiles entangled in various errors might by this sign of Divine mercy be chiefly invited to come to hope, seeing that to them even who crucified the Son of God pardon is granted.

But herein that He says, Repentance and remission of sins, He also makes mention of baptism, in which by the putting off of our past sins there follows pardon of iniquity. But how must we understand baptism to be performed in the name of Christ alone, whereas in another place He commands it to be in the name of the Father, and the Son, and the Holy Ghost. First indeed we say that it is not meant that baptism is administered in Christ's name alone, but that a person is baptized with the baptism of Christ, that is, spiritually, not Judaically, nor with the baptism, wherewith John baptized unto repentance only, but unto the participation of the blessed Spirit; as Christ also when baptized in Jordan manifested the Holy Spirit in the form of a dove. Moreover you must understand baptism in Christ's name to be in His death. For as He after death rose again on the third day, so we also are three times dipped in the water, and fitly brought out again, receiving thereby an earnest of the immortality of the Spirit. This name of Christ also contains in itself both the Father as the Anointer, and the Spirit as the Anointing, and the Son as the Anointed, that is, in His human nature. But it was fitting that the race of man should no longer be divided into Jews and Gentiles, and therefore that He might unite all in one, He commanded that their preaching should begin at Jerusalem, but be finished with the Gentiles. Hence it follows, Beginning at Jerusalem. (Rom. 3:2, Rom. 9:4.)

But Christ would have lost the fruit of His Passion had He not been the Truth of the resurrection, therefore it is said, And to rise from the dead. He then after having commended to them the truth of the body, commends the unity of the Church, adding, And that repentance and remission of sins should be preached in his name among all nations.