Chapter 37.
85 Petilianus said: "But that the truth of this may be made manifest from the apostles, we are taught by their actions, as it is written: ‘It came to pass that while Apollos was at Corinth, Paul, having passed through the upper coasts, came to Ephesus; and finding certain disciples, he said unto them, Have ye received the Holy Ghost since you believed? And they said unto him, We have not so much as heard whether there be any Holy Ghost. And he said unto them, Unto what then were ye baptized? And they said, Unto John's baptism. Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe in Him which should come after him, that is, on Christ Jesus. When they heard this, they were baptized in the name of the Lord Jesus. And when Paul had laid his hands upon them, the Holy Ghost came on them; and they spoke with tongues, and prophesied. And all the men were about twelve.' If, therefore, they were baptized that they might receive the Holy Ghost, why do not you, if you wish to receive the Holy Ghost, take measures to obtain a true renewing, after your falsehoods? And if we do ill in urging this, why do you seek after us? Or at any rate, if it is an offense, condemn Paul in the first instance; the Paul who certainly washed off what had already existed, whereas we in you give baptism which as yet does not exist. For you do not, as we have often said before, wash with a true baptism; but you bring on men an ill repute by your empty name of a false baptism."
86. Augustine answered: "We bring no accusation against Paul, who gave to men the baptism of Christ because they had not the baptism of Christ, but the baptism of John, according to their own reply; for, being asked, Unto what were ye baptized? They answered, Unto John's baptism; which has nothing to do with the baptism of Christ, and is neither a part of it nor a step towards it. Otherwise, either at that time the water of the baptism of Christ was renewed a second time, or if the baptism of Christ was then made perfect by the two waters, the baptism is less perfect which is given now, because it is not given with the water which was given at the hands of John. But either one of these opinions it is impious and sacrilegious to entertain. Therefore Paul gave the baptism of Christ to those who had not the baptism of Christ, but only the baptism of John.
87. But why the baptism of John, which is not necessary now, was necessary at that time, I have explained elsewhere; and the question has no bearing on the point at issue between us at the present time, except so far as that it may appear that the baptism of John was one thing, the baptism of Christ another—just as that baptism was a different thing with which the apostle says that our fathers were baptized in the cloud and in the sea, when they passed through the Red Sea under the guidance of Moses. For the law and the prophets up to the time of John the Baptist had sacraments which foreshadowed things to come; but the sacraments of our time bear testimony that that has come already which the former sacraments foretold should come. John therefore was a foreteller of Christ nearer to Him in time than all who went before him. And because all the righteous men and prophets of former times desired to see the fulfillment of what, through the revelation of the Spirit, they foresaw would come to pass—whence also the Lord Himself says, "That many prophets and righteous men have desired to see those things which you see, and have not seen them; and to hear those things which you hear, and have not heard them," — therefore it was said of John that he was more than a prophet, and that among all that were born of women there was none greater than he; because to the righteous men who went before him it was only granted to foretell the coming of Christ, but to John it was given both to foretell Him in His absence and to behold His presence, so that it should be found that to him was made manifest what the others had desired. And therefore the sacrament of his baptism is still connected with the foretelling of Christ's coming, though as of something very soon to be fulfilled, seeing that up to his time there were still foretellings of the first coming of our Lord, of which coming we have now announcements, but no longer predictions. But the Lord, teaching the way of humility, condescended to make use of the sacraments which He found here in reference to the foretelling of His coming, not in order to assist the operation of His cleansing, but as an example for our piety, that so He might show to us with what reverence we ought to receive those sacraments which bear witness that He is already come, when He did not disdain to make use of those which foreshadowed His coming in the future. And John, therefore, though the nearest to Christ in point of time, and within one year of the same age with Him, yet, while he was baptizing, went before the way of Christ who was still to come; for which reason it was said of him, "Behold, I send my messenger before Your face, which shall prepare Your way before You." And he himself preached, saying, "There comes one mightier than I after me." In like manner, therefore, the circumcision on the eighth day, which was given to the patriarchs, foretold our justification, to the putting away of carnal lusts through the resurrection of our Lord, which took place after the seventh day, which is the Sabbath day, on the eighth, that is, the Lord's day, which fell on the third day after His burial; yet the infant Christ received the same circumcision of the flesh, with its prophetic signification. And as the Passover, which was celebrated by the Jews with the slaying of a lamb, prefigured the passion of our Lord and His departure from this world to the Father, yet the same Lord celebrated the same Passover with His disciples, when they reminded Him of it, saying, Where will You that we prepare for You to eat the Passover? so too He Himself also received the baptism of John, which formed a part of the latest foretelling of His coming. But as the Jews' circumcision of the flesh is one thing, and the ceremony which we observe on the eighth day after persons are baptized is another; and the Passover which the Jews still celebrate with the slaying of a lamb is one thing, and that which we receive in the body and blood of our Lord is another—so the baptism of John was one thing, the baptism of Christ is another. For by the former series of rites the latter were foretold as destined to arrive; by these latter the others are declared to be fulfilled. And even though Christ received the others, yet are they not necessary for us, who have received the Lord Himself who was foretold in them. But when the coming of our Lord was as yet recent, it was necessary for any one who had received the former that he should be imbued with the latter also; but it was wholly needless that any one who had been so imbued should be compelled to go back to the former rites.
Source: Answer to Letters of Petilian, Bishop of Cirta (New Advent)