A ransom for many
Even as the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many. Matthew 20:28
How was the atonement meant to show God’s love to us? “God so loved the world that he gave his only Son” – yes, but why? Why did God’s love for mankind propel him to send his Son to die? To say that the reason Christ died was no more than to show his love for us doesn’t make sense. Why did he have to show his love by dying for us? There must have been a reason why his love for us drove him to the cross. As R. W. Dale has explained, “If my brother made his way into a burning house to save my child from the flames, and were himself to perish in his heroic venture, his fate would be a wonderful proof of his affection for me and mine; but if there were no child in the house, and if I were told that he entered it and perished with no other object in mind than to show his love for me, the explanation would be absolutely unintelligible.” In other words, if Jesus died simply to show his love for us and thereby motivate us to love him, that would be as crazy as a friend throwing himself off a cliff just to show his love for you. That is not love; that is a sick psychological disorder, and completely unworthy of what we know of Christ in the pages of the NT.
The fact of the matter is that you don’t have to die to set an example or to show your love for someone or to influence them to do good. And yet the gospels make it very clear that the death of Jesus had to happen. As Jesus explained it to the apostles in Mt. 16:21, “he must go unto Jerusalem, and suffer many things . . . and be killed, and be raised again the third day.” But again, why?
The explanation comes in our text, in Matthew 20:28. Here the words of Jesus interpret the works of Jesus: “Even as the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.” In this text, our Lord says that his life is not fundamentally an example, but a ransom for many. These words are very significant. They tell us that the death of Jesus was a substitutionary sacrifice, and that in dying he paid a ransom for the lives of many. In the death of Christ there was an exchange – Christ exchanged his life for the salvation of others. His life was the price that had to be paid for the release of many sinful men and women from the guilt and grip of sin. And to underline this fact, Matthew records Jesus’ words not only with the word for “ransom” (lutron) but with the word anti(“for”) whose normal force “denotes substitution, equivalence, exchange.” In other words, this verse very clearly supports the doctrine of substitutionary atonement – the doctrine that says that the meaning of the atonement lies in the substitution of Jesus for sinners in order to pay the penalty for their sin.
Now a lot of people despise this doctrine because they can’t understand how one person can stand for someone else and take the punishment of their sins. And the fact of the matter is that no mere man or woman can do this. But that does not mean that God cannot do it. Our Lord has already reminded us in the previous verses that the things that are impossible with men are possible with God (19:26). This is one such thing. I cannot take your punishment nor you mine; but God in human flesh is able to bare the sins of many. He is like us so that he is able to identify with us; and he is unlike us so that he is able to take our sin upon himself and purge it.
Our Lord came to meet a desperate need, one that we could never have met. He did not come to stupidly run into a burning building just to show his love. No, he came out of love for us because we were in the burning building. And we were the ones who set it on fire. And as it burned around us, we had no way out. Our sins started the fire and our sins chained us to the burning building. By all rights, we should have died. And then Jesus came, burst through the building, cut through the chains and set us free. But it cost him his life. It was his life for ours. He paid the ransom so that we could be free.
He didn’t have to do this. Our sins are noxious and putrid. There is nothing in us that commends us to God. It was not even our love for him, for apart from his grace, we have no love of God or his law. He first loved us, and then took upon himself the exceedingly difficult journey of redemption. There was nothing glorious about the lifelong journey of Jesus upon the earth; there was certainly nothing glorious about his death: “this is to be no glorious martyrdom, but an ugly, sordid butchery.” Behold the love of Christ! Let us trust not in our good works but in the finished work of Jesus Christ the Son of God.
 From his work The Atonement, quoted by William Lane Craig in http://www.reasonablefaith.org/the-need-for-a-multi-faceted-atonement-doctrine
 D. A. Carson, Matthew (EBC), p. 433.
 R. T. France, Matthew (TNTC), p. 291.