We are sure ... - See a similar confession of Peter in Matthew 16:16, and the notes at that place. Peter says we are sure, in the name of the whole of the apostles. Jesus immediately cautions him, as he did on other occasions, not to be too confident, for one of them actually had no such feelings, but was a traitor.

We believe - On the authority of thy word; and are sure - have known, εγνωκαμεν, by the evidence of thy miracles, that thou art the Christ, the promised Messiah. And we belyfath and witen that thu eart Crist Godes Son. Anglo-Saxon. How near is the mother to the daughter tongue!

Instead of Christ the Son of the living God, some excellent MSS., BCDL, and others, read ὁ αγιος του Θεου, the holy one of God; and this reading Griesbach has received into the text, leaving out του ζωντος, the living. Χριστος, and ἁγιος convey nearly the same meaning; but the Ethiopic, as usual, retains both. Του ζωντες is omitted by BCDL, H, the Coptic, Sahidic, Armenian, later Persic, Vulgate, all the Itala but one, and by the Anglo-Saxon; which last Griesbach has not noticed.

And we believe and are sure,.... Or know of a certainty: they believed upon the first call of them by Christ, and their following of him, that he was the true Messiah; and they came to an assurance of it, by the miracles he wrought, and by the doctrines which he taught; their faith, how weak soever it might be at first, rose up to a full assurance of faith, and of understanding; there was a reality and a certainty in it, as there is in all true faith, with respect to the object, though not always with respect to interest in it; which was the case here, as appears by what follows:

that thou art that Christ; or Messiah, that was promised by God of old, spoken of by the prophets, and expected by the Jews; that anointed prophet Moses had spoken of, that should arise out of Israel, like unto him that anointed priest, who, according to the oath of God, was to be priest for ever, after the order of Melchizedek; and that anointed King, whom God has set over his holy hill of Zion:

the son of the living God; this they knew, and were sure of, both by John's testimony, and by the father's voice from heaven; which three of them heard, at Christ's transfiguration on the mount: God the father is called "the living God"; though the Vulgate Latin version leaves out the word "living"; not to distinguish him from his son; for he also is the living God; and is so called, Hebrews 3:12, but to distinguish him from the idols of the Gentiles, who have no life nor breath in them: and Christ is called the son of the living God, as he is a divine person, as he is truly God; and to show that he has the same life his father has; being a partaker of the same nature, and divine perfections: and this is another reason why sensible souls will go to Christ, and no other; because he is the Messiah, the Saviour, and Redeemer, and an able one; and because he is God, and there is none else.

Are sure (ἐγνώκαμεν)

Literally, have come to know. The order of the words believe and know is reversed in John 17:8; 1 John 4:16. In the case of the first disciples, faith, produced by the overpowering impression of Jesus' works and person, preceded intellectual conviction.

That Christ, the Son of the living God

The best texts substitute ὁ ἅγιος τοῦ Θεοῦ, the holy one of God. The other reading has resulted from the attempt to bring Peter's confession here into accord with that in Matthew 16:16. The two confessions differ in that "here the confession points to the inward character in which the Apostles found the assurance of life; there the confession was of the public office and theocratic person of the Lord" (Westcott).

And we believe and are sure that thou art that Christ, the Son of the living God.

6:68,69 To whom shall we go? If we should turn from Christ, to whom should we go? Peter's confession here is of the same purport as that a Caesarea Philippi.

6:69 And we - Who have been with thee from the beginning, whatever others do, have known - Are absolutely assured, that thou art the Christ.

Margin we believe

Or, we have believed and come to understand that thou art the Holy One of God.

69. And we believe,-(See on [1797]Mt 16:16). Peter seems to have added this not merely-probably not so much-as an assurance to his Lord of his heart's belief in Him, as for the purpose of fortifying himself and his faithful brethren against that recoil from his Lord's harsh statements which he was probably struggling against with difficulty at that moment. Note.-There are seasons when one's faith is tried to the utmost, particularly by speculative difficulties; the spiritual eye then swims, and all truth seems ready to depart from us. At such seasons, a clear perception that to abandon the faith of Christ is to face black desolation, ruin and death; and on recoiling from this, to be able to fall back, not merely on first principles and immovable foundations, but on personal experience of a Living Lord in whom all truth is wrapt up and made flesh for our very benefit-this is a relief unspeakable. Under that blessed Wing taking shelter, until we are again fit to grapple with the questions that have staggered us, we at length either find our way through them, or attain to a calm satisfaction in the discovery that they lie beyond the limits of present apprehension.

6:66-71 When we admit into our minds hard thoughts of the words and works of Jesus, we enter into temptation, which, if the Lord in mercy prevent not, will end in drawing back. The corrupt and wicked heart of man often makes that an occasion for offence, which is matter of the greatest comfort. Our Lord had, in the foregoing discourse, promised eternal life to his followers; the disciples fastened on that plain saying, and resolved to cleave to him, when others fastened on hard sayings, and forsook him. Christ's doctrine is the word of eternal life, therefore we must live and die by it. If we forsake Christ, we forsake our own mercies. They believed that this Jesus was the Messiah promised to their fathers, the Son of the living God. When we are tempted to backslide or turn away, it is good to remember first principles, and to keep to them. And let us ever remember our Lord's searching question; Shall we go away and forsake our Redeemer? To whom can we go? He alone can give salvation by the forgiveness of sins. And this alone brings confidence, comfort, and joy, and bids fear and despondency flee away. It gains the only solid happiness in this world, and opens a way to the happiness of the next.