(21) But all these things will they do unto you.--These words are themselves an interpretation of the previous verse. They suppose the persecution and hatred to take place, and find the true consolation in the fact that this would be done to them as representing their Lord. The Acts of the Apostles and the Epistles are a commentary on this text. (Comp., among numerous passages, Acts 4:17; Acts 9:14; Galatians 6:17.)

Because they know not him that sent me.--The hatred is here traced to its true cause, which is ignorance of God. The Apostles were those sent by Christ. He Himself was the Apostle of the Father. They would hate His messenger, and hate Him, the messenger of God, because they knew not God.

Verse 21. - But all these things will they do unto you. By way of consolation, he added, in view of the antagonism which the world would deliberately pursue towards them, For my Name's sake. Many suppose that the consolatory element is emphasized in this clause. However, the idea contained in the διὰ τὸ ὀνομά μου has been already expressed in the previous verses, and the whole of the verse so far merely gathers it up for a new and suggestive explanation. For the Name of Christ these disciples will not only pray, labor, suffer, and die, but in the power of it they will transmute their sorrows into raptures, their tribulations into glory. Because they know not him that sent me. If they had known the heart and nature of the Sender, they would have understood the mission of the Savior, and would neither have hated him nor his representations. (Here Lucke, Hengstenberg, Luthardt, and Lange are preferable to Meyer and Godet.) It is utter grief to Jesus that the world has been ignorant of the Father. This ignorance explains its antagonism to the representatives of Christ, and is the most appalling witness to its own depravation. No fact is more patent in the entire history of human thoughts about God than this, that "the world by wisdom knows him not," nay, it travesties his Name, misrepresents his character, distrusts, fears, and flees from the face of God. It was left to Christ to reveal the Father. In many different mental tendencies even Christendom has obscured or denied the Fatherhood.

15:18-25 How little do many persons think, that in opposing the doctrine of Christ as our Prophet, Priest, and King, they prove themselves ignorant of the one living and true God, whom they profess to worship! The name into which Christ's disciples were baptized, is that which they will live and die by. It is a comfort to the greatest sufferers, if they suffer for Christ's name's sake. The world's ignorance is the true cause of its hatred to the disciples of Jesus. The clearer and fuller the discoveries of the grace and truth of Christ, the greater is our sin if we do not love him and believe in him.But all these things will they do unto you,.... Christ here signifies, that all the hatred and persecutions raised against his people by the world, would not be on their own account, for any evil actions done by them; they would not suffer as thieves, murderers, and evildoers, but as Christians; or as he says,

for my name's sake: because they were called by his name, and called upon his name; because they professed his name, and confessed him to be the Messiah and Redeemer; because they loved his name Jesus, a Saviour, believed in his name, and hoped in him for eternal life; and also preached him, and in his name salvation, and encouraged others to believe in him; and therefore they had no reason to be ashamed, but rather to rejoice; as they afterwards did, that they were counted worthy to suffer shame for his name: besides, this malice and hatred of theirs arose from ignorance of the Father of Christ:

because they know not him that sent me; they did not know that Jesus was the Christ, and sent of God; they did not acknowledge him to be so, or the Father to be the sender of him; and because Christ and his disciples asserted this, therefore they were the objects of their hatred.