Matthew 16:17

But in heavenly things every spiritual sin is a gate of hell, to which are opposed the gates of righteousness. He does not express what it is which they shall not prevail against, whether the rock on which He builds the Church, or the Church which He builds on the rock; but it is clear that neither against the rock nor against the Church will the gates of hell prevail. Wherefore if we, by the revelation of our Father who is in heaven, shall confess that Jesus Christ is the Son of God, having also our conversation in heaven, to us also shall be said, Thou art Peter; for every one is a Rock who is an imitator of Christ. But against whomsoever the gates of hell prevail, he is neither to be called a rock upon which Christ builds His Church; neither a Church, or part of the Church, which Christ builds upon a rock.

This confession of Peter met a worthy reward, for that he had seen the Son of God in the man. Whence it follows, Jesus answered and said unto him, Blessed art thou, Simon Barjonas, for flesh and blood has not revealed this unto thee, but my Father who is in heaven. Otherwise; He is blessed, because to have looked and to have seen beyond human sight is matter of praise, not beholding that which is of flesh and blood, but seeing the Son of God by the revelation of the heavenly Father; and he was held worthy to be the first to acknowledge the divinity which was in Christ.

What then saith Christ? "Blessed art thou, Simon Barjona, for flesh and blood hath not revealed it unto thee." Yet surely unless he had rightly confessed Him, as begotten of the very Father Himself, this were no work of revelation; had he accounted our Lord to be one of the many, his saying was not worthy of a blessing. Since before this also they said, "Truly He is Son of God," those, I mean, who were in the vessel after the tempest, which they saw, and were not blessed, although of course they spake truly. For they confessed not such a Sonship as Peter, but accounted Him to be truly Son as one of the many, and though peculiarly so beyond the many, yet not of the same substance. And Nathanael too said, "Rabbi, Thou art the Son of God, Thou art the King of Israel;" and so far from being blessed, he is even reproved by Him, as having said what was far short of the truth. He replied at least, "Because I said unto thee, I saw thee under the fig-tree, believest thou? thou shalt see greater things than these." Why then is this man blessed? Because he acknowledged Him very Son. Wherefore you see, that while in those former instances He had said no such thing, in this case He also signifies who had revealed it. That is, lest his words might seem to the many (because he was an earnest lover of Christ) to be words of friendship and flattery, and of a disposition to show favor to Him, he brings forward the person who had made them ring in his soul; to inform thee that Peter indeed spake, but the Father suggested, and that thou mightest believe the saying to be no longer a human opinion, but a divine doctrine. And wherefore doth He not Himself declare it, nor say, "I am the Christ," but by His question establish this, bringing them in to confess it? Because so to do was both more suitable to Him, yea necessary at that time, and it drew them on the more to the belief of the things that were said. Seest thou how the Father reveals the Son, how the Son the Father? For "neither knoweth any man the Father," saith He, "save the Son, and he to whomsoever the Son will reveal Him." It cannot therefore be that one should learn the Son of any other than of the Father; neither that one should learn the Father of any other than of the Son. So that even hereby, their sameness of honor and of substance is manifest.

This return Christ makes to the Apostle for the testimony which Peter had spoken concerning Him, Thou art Christ, the Son of the living God. The Lord said unto him, Blessed art thou, Simon Bar-jonas? Why? Because flesh and blood has not revealed this unto thee, but My Father. That which flesh and blood could not reveal, was revealed by the grace of the Holy Spirit. By his confession then he obtains a title, which should signify that he had received a revelation from the Holy Spirit, whose son he shall also be called; for Barjonas in our tongue signifies The son of a dove. Others take it in the simple sense, that Peter is the son of Johnq, according to that question in another place, Simon, son of John, lovest thou me? (John 21:15.) affirming that it is an error of the copyists in writing here Barjonas for Barjoannas, dropping one syllable. Now Joanna is interpreted 'The grace of God.' But either name has its mystical interpretation; the dove signifies the Holy Spirit; and the grace of God signifies the spiritual gift. Compare what is here said, flesh and blood hath not revealed it unto thee, with the Apostolic declaration, Immediately I was not content with flesh and blood, (Gal. 1:16.) meaning there by this expression the Jews; so that here also the same thing is shown in different words, that not by the teaching of the Pharisees, but by the grace of God, Christ was revealed to him the Son of God.