John 6:36

36.But I have told you. He now reproves them for wickedly rejecting the gift of God, which is offered to them. Now, that man is chargeable with wicked contempt of God, who rejects what he knows that God has given him. If Christ had not made known his power, and plainly showed that he came from God, the plea of ignorance might have alleviated their guilt; but when they reject the doctrine of him whom they formerly acknowledged to be the Lord’s Messiah, it is extreme baseness. It is no doubt true, that men never resist God purposely, so as to reflect that they have to do with God; and to this applies the saying of Paul,

They would never have crucified the Lord of glory, if they had known him
(1 Corinthians 2:8.)

But unbelievers, because they willingly shut their eyes against the light are justly said to see that which immediately vanishes from their sight, because Satan darkens their understandings. This, at least, is beyond all controversy, that when he said that they saw, we must not understand him to mean his bodily appearance, but rather that he describes their voluntary blindness, because they might have known what he was, if their malice had not prevented them.