Acts 10:47

Neither, for a like reason, would he have given them baptism so readily, had he not heard them prophesying when the Holy Ghost rested upon them. And therefore did he exclaim, "Can any man forbid water, that these should not be baptized, who have received the Holy Ghost as well as we?" He persuaded, at the same time, those that were with him, and pointed out that, unless the Holy Ghost had rested upon them, there might have been some one who would have raised objections to their baptism.

We have thought it necessary for the arranging of certain matters, dearest brother, and for their investigation by the examination of a common council, to gather together and to hold a council, at which many priests were assembled at once; at which, moreover, many things were brought forward and transacted. But the subject in regard to which we had chiefly to write to you, and to confer with your gravity and wisdom, is one that more especially pertains both to the priestly authority and to the unity, as well as the dignity, of the Catholic Church, arising as these do from the ordination of the divine appointment; to wit, that those who have been dipped abroad outside the Church, and have been stained among heretics and schismatics with the taint of profane water, when they come to us and to the Church which is one, ought to be baptized, for the reason that it is a small matter to "lay hands on them that they may receive the Holy Ghost," unless they receive also the baptism of the Church. […]

That the need of water is absolute and indispensable, you may learn in this way. On one occasion, when the Spirit had flown down before the water was applied, the Apostle did not stay at this point, but, as though the water were necessary and not superfluous, observe what he says; "Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?"

Peter seizes his advantage, and see the plea he makes of it. "Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?" Mark the issue to which he brings it; how he has been travailing to bring this forth. So entirely was he of this mind! "Can any one," he asks, "forbid water?" It is the language, we may almost say, of one triumphantly pressing his advantage against such as would forbid, such as should say that this ought not to be. The whole thing, he says, is complete, the most essential part of the business, the baptism with which we were baptized.

For since a person is of twofold nature, soul and body, the purification also is twofold, the one incorporeal for the incorporeal part, and the other bodily for the body. The water cleanses the body, and the Spirit seals the soul, that we may draw near to God, "having our heart sprinkled" by the Spirit "and our body washed with pure water." … Neither does he who is baptized with water, but not found worthy of the Spirit, receive the grace in perfection; nor if a person is virtuous in his deeds, but receives not the seal by water, shall he enter into the kingdom of heaven. A bold saying, but not mine, for it is Jesus who has declared it, and here is the proof of the statement from holy Scripture. Cornelius was a just man who was honored with a vision of angels and had set up his prayers and alms deeds as a good memorial before God in heaven. Peter came, and the Spirit was poured out on them that believed, and they spoke with other tongues and prophesied. And after the grace of the Spirit the Scripture says that Peter commanded them to be baptized in the name of Jesus Christ; in order that, the soul having been born again by faith, the body also might by the water partake of the grace.