Jesus knew from the beginning ... - As this implied a knowledge of the heart, and of the secret principles and motives of men, it shows that he must have been omniscient.

But there are some of you that believe not - This is addressed to Judas, and to those disciples who left him: John 6:66.

And who should betray him - Or, who would deliver him up. Because he knew all things; he knew from the first, from Judas's call to the apostleship, and from eternity, (if the reader pleases), who it was who would (not should) deliver him up into the hands of the Jews. Should, in the apprehension of most, implies necessity and compulsion; would implies that he was under the influence of his own free will, without necessity or constraint. The former takes away his guilt: for what a man is irresistibly compelled to do, by the supreme authority of God, he cannot avoid; and therefore to him no blame can attach: but Judas having acted through his own free will, abusing his power, and the grace he had received, he was guilty of the murder of an innocent man, and deserved the perdition to which he went.

But there are some of you that believe not,.... Notwithstanding the ministry they sat under, and the words they heard; for though they professed to believe in Jesus, as the Messiah, yet they did not truly believe in him; their faith was not a living faith, or of a spiritual kind, but a mere historical and temporary one, and was feigned and hypocritical:

for Jesus knew from the beginning; of his ministry, and of their profession of him, being God omniscient, and the searcher of hearts:

who they were that believed not; i.e. in him, as the Arabic version reads: notwithstanding their following him, and professing to believe in him, and the great outward respect and esteem they showed to him, he could see through all those masks they put on, and knew they had no true faith of him in them; and the same knowledge he has of every professor of his name: he knows whether their faith is of the right kind or not; whether they have obtained the like precious faith with God's elect; or whether their profession is only a verbal one. In some copies it is read, "who they were that believed"; who were true believers, as well as who were hypocrites.

And who should betray him: he not only knew how it was with the multitude of the disciples that professed love to him, and faith in him; but he also particularly knew the case of the twelve apostles, and that one of them should betray him, and who he was. This was determined in the decrees of God, and was foretold in the prophecies of the Old Testament, and was predicted by Christ; and the person was pointed at by him before it was done.

Should betray (παραδώσων)

See on Matthew 4:12; see on Mark 4:29. Judas is once in the New Testament designated by the noun προδότης, traitor, Luke 6:16.

But there are some of you that believe not. For Jesus knew from the beginning who they were that believed not, and who should betray him.

6:64 But there are some of you who believe not - And so receive no life by them, because you take them in a gross literal sense. For Jesus knew from the beginning - Of his ministry: who would betray him - Therefore it is plain, God does foresee future contingencies: But his foreknowledge causes not the fault, Which had no less proved certain unforeknown.

64. But there are some, &c.-that is, "But it matters little to some of you in what sense I speak, for ye believe not." This was said, adds the Evangelist, not merely of the outer but of the inner circle of His disciples; for He knew the traitor, though it was not yet time to expose him.

6:60-65 The human nature of Christ had not before been in heaven, but being God and man, that wondrous Person was truly said to have come down from heaven. The Messiah's kingdom was not of this world; and they were to understand by faith, what he had said of a spiritual living upon him, and his fulness. As without the soul of man the flesh is of no value, so without the quickening Spirit of God all forms of religion are dead and worthless. He who made this provision for our souls, alone can teach us these things, and draw us unto Christ, that we may live by faith in him. Let us apply to Christ, thankful that it is declared that every one who is willing to come unto him shall be made welcome.