In Against Heresies 3.12.7, Ireneus did not believe that Cornelius was saved outside of the reception of water baptism, something many critics of the doctrine of baptismal regeneration claim:
From the words of Peter, therefore,
which he addressed in Cæsarea to Cornelius the centurion, and those Gentiles
with him, to whom the word of God was first preached, we can understand what
the apostles used to preach, the nature of their preaching, and their idea with
regard to God. For this Cornelius was, it is said, “a devout man, and one who
feared God with all his house, giving much alms to the people, and praying to
God always. He saw therefore, about the ninth hour of the day, an angel of God
coming in to him, and saying, Thine alms are come up for a memorial before God.
Wherefore send to Simon, who is called Peter.” But when Peter saw the vision,
in which the voice from heaven said to him, “What God hath cleansed, that call
not thou common,” this happened [to teach him] that the God who had, through
the law, distinguished between clean and unclean, was He who had purified the
Gentiles through the blood of His Son—He whom also Cornelius worshipped; to
whom Peter, coming in, said, “Of a truth I perceive that God is no respecter of
persons: but in every nation, he that feareth Him, and worketh righteousness,
is acceptable to Him.” He thus clearly indicates, that He whom Cornelius had
previously feared as God, of whom he had heard through the law and the
prophets, for whose sake also he used to give alms, is, in truth, God. The
knowledge of the Son was, however, wanting to him; therefore did [Peter] add,
“The word, ye know, which was published throughout all Judea, beginning from
Galilee, after the baptism which John preached, Jesus of Nazareth, how God
anointed Him with the Holy Ghost, and with power; who went about doing good, and
healing all that were oppressed of the devil; for God was with Him. And we are
witnesses of all those things which He did both in the land of the Jews and in
Jerusalem; whom they slew, hanging Him on a beam of wood: Him God raised up the
third day, and showed Him openly; not to all the people, but unto us, witnesses
chosen before of God, who did eat and drink with Him after the resurrection
from the dead. And He commanded us to preach unto the people, and to testify
that it is He which was ordained of God to be the Judge of quick and dead. To
Him give all the prophets witness, that, through His name, every one that
believeth in Him does receive remission of sins.” The apostles, therefore, did
preach the Son of God, of whom men were ignorant; and His advent, to those who
had been already instructed as to God; but they did not bring in another God.
For if Peter had known any such thing, he would have preached freely to the
Gentiles, that the God of the Jews was indeed one, but the God of the
Christians another; and all of them, doubtless, being awe-struck because of the
vision of the angel, would have believed whatever he told them. But it is
evident from Peter’s words that he did indeed still retain the God who was
already known to them; but he also bare witness to them that Jesus Christ was
the Son of God, the Judge of quick and dead, into whom he did also command them
to be baptized for the remission of sins; and not this alone, but he witnessed
that Jesus was Himself the Son of God, who also, having been anointed with the
Holy Spirit, is called Jesus Christ. And He is the same being that was born of
Mary, as the testimony of Peter implies. Can it really be, that Peter was not
at that time as yet in possession of the perfect knowledge which these men
discovered afterwards? According to them, therefore, Peter was imperfect, and
the rest of the apostles were imperfect; and so it would be fitting that they,
coming to life again, should become disciples of these men, in order that they
too might be made perfect. But this is truly ridiculous. These men, in fact,
are proved to be not disciples of the apostles, but of their own wicked
notions. To this cause also are due the various opinions which exist among
them, inasmuch as each one adopted error just as he was capable [of embracing
it]. But the church throughout all the world, having its origin firm from the
apostles, perseveres in one and the same opinion with regard to God and His
Son.