“For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life.” (John 3:16)
Notice that Christ represents the Father to us as none else than the all-loving and magnetic one, and he brings us through himself to the Father. Everything Christ does tends to help us to acquire a loving confidence in the Father. To simply fear the Father confers no benefit; but to bear to him a companionable love of rare quality makes us blessed. Now, Christ says here, the Father so loved the world that he gave his beloved child for the world, and instituted for us a way to come to him; that way is Christ.
What is now the cost of redemption? The text points this out. The Holy Spirit teaches everywhere that we do not possess the Father except through a mediator, and he will not allow us to approach the Father without one. Now, some teach us to approach the Father without a mediator, through our own good works. That means to reject Christ as a mediator, as Jeremiah tells us did the godless, who thought and said: Let us send wood to him as his food, and we will root him out of the land, and there will be no remembrance of his name. But their plans did not result as they intended they should. Therefore, let us never join them. It would be at the peril of our lives, for we should be despising the priceless sacrifice which the Father made for us. But let us thank the Father for ordering it as he has, and placing between us one who is God and equal with God, and also man, on a level with man; for we are human and he is God. Where God and man oppose each other, man meets with instant destruction, for he cannot stand against God. God has intervened by placing as mediator one who is alike true God and true man. Through him we are to come to the Father; with the price we can pay nothing is accomplished.
Now, those who teach that man is to be saved by his own works; they say: Whosoever becomes a monk or nun, or repeats every day the little prayer of a Saint, shall be eternally saved. This is no less than saying: I will work enough to escape perdition; I will turn my sins into vapor, to disappear and open a way into heaven. They wish to discover the sacrifice or price of salvation in themselves and to ignore Christ as mediator. But they will perish, since they fain would come to the Father without a mediator, without Christ, whom the Father holds up before us out of his gracious goodness. Christ teaches here that we are not lost, but have eternal life; that is, that God has so loved us that he allowed the ransom to cost him his only beloved child. Him he placed in our stead to suffer misery, hell and death, and let him drink our cup to the dregs. This is the way we are to be saved.
Now, if there were another way to heaven doubtless he would have made it known to us. There is no other. Therefore, let us cling to the words, firmly pilot our hearts along this way and keep within it, and let us close our eyes and say: If I had the merits of all the saints, the sanctity and purity of all virgins, and the piety of St. Peter besides, still I would not give a fig for all I call my own. I must have another foundation on which to build, namely, the words: God has given his Son, that whosoever believeth on him, whom the Father sent out of love, shall be saved. And let us defiantly boast that we must be sustained. Let us fearlessly establish ourselves upon his words, which neither Satan, hell nor death can overthrow, for the Father mightily writes his Word over these terrors and all that clings to them. Come what will, let us say: Here is God's Word; that is my rock and anchor; to that I cling and that abides; and where that abides, there I abide also. For God cannot lie; sooner would the heavens and earth perish than the smallest letter or tittle of his Word would fail.