Mark that He does not say that He shall suffer. Certainty is not all that He proclaims here, however absolute that certainty might be, but it is He must: He is speaking not only of the historical fact, but of the need, deep in the nature of things, for His sufferings that were to follow.
And though these were wrought out by His own willing submission on the one hand, and by the unfettered play of the evil passions of the worst of men on the other, yet over all that apparent chaos of unbridled devildom there ruled the Unalterable purpose of God; and the must' was wrought out through the passions of evil-doers and the voluntary submission of the innocent sufferer; thus setting before us, in the central fact of the history of humanity, viz. the Cross and passion of Jesus Christ, the eminent example of that great mystery how the absolute freedom of the human will, and the responsibility of the guilt of human wrong-doers, are congruous with the fixed purpose of an all-determining and all-ruling Providence.
But that is apart from my purpose. Mark then, that our Lord's recognition of this necessity for His suffering is, on the first and plainest aspect of it, His recognition that His suffering was necessary on the ground of filial obedience. All through His life we hear that must' echoing, and His whole spirit bowed to it. As He says Himself, The Son can do nothing of Himself.' As was said for Him of old: Lo, I come. In the volume of the book it is written of Me, I delight to do Thy will, and Thy law is within My heart.' So the Father's will is the Son's law; and the Father's Thou shalt' is answered by the Son's I must.'
But yet that necessity grounded on filial obedience was no mere external necessity determined solely by the divine will. God so willed it, because it must be so; that it must be so was not because God so willed it. That is to say, the work to which Christ had set His hand was a work that demanded the Cross, nor could it be accomplished without it. For it was the work of redeeming the world, and required more than a beautiful life, more than a divine gentleness of heart, more than the homely and yet deep wisdom of His teachings, it required the sacrifice that He offered on the Cross.
So, dear friends, Christ's must' is but this: My work is not accomplished except I die.' And remember that the connection between our Lord's work and our Lord's death is not that which subsists between the works and the deaths of great teachers, or heroic martyrs, or philanthropists and benefactors, who will gladly pay the price of life in order to carry out their loving or their wise designs. It is no mere appendage to His work, nor the price that He paid for having done it, but it is His very work in its vital centre.
I pray you to consider if there is any theory of the meaning and power of the death of Jesus Christ which adequately explains this must,' except the one that He died a sacrifice for the sins of the world. On any other hypothesis, as it seems to me, of what His death meant, it is surplusage, over and above His work: not adding much, either to His teaching or to the beauty of His example, and having no absolute stringent necessity impressed upon it. There is one doctrine--that when He died He bare the sins of the whole world--which makes His death a necessity; and I ask you, Is there any other doctrine which does? Take care of a Christianity which would not be much impoverished if the Cross were struck out of it altogether.
There is a deeper question, on which, as I believe, it does not become us to enter, and that is, What is the necessity for the necessity? Why must it be that He, who is the Redeemer of the world, must needs be the Sacrifice for the world? We do not know enough about the depths of the divine nature and the divine government to speak very wisely or reverently upon that subject, and I, for one, abjure the attempt, which seems to me to be presumptuous--the attempt to explain why there was needed a sacrifice for sin in order to the forgiveness of sin. If I knew all about God, I could tell you; and nobody, that does not, can. But we can see, as far as concerns us, that, as the history of all religions tells us, for the forgiveness and acceptance of sinful men a pure sacrifice is needed; and that for teaching us the love of God, the hideousness and wages of sin, for our emancipation from evil, for the quieting of our consciences, for a foothold for faith, for an adequate motive of self-surrender and obedience, his sacrificial death is needful. The life and death of Jesus Christ, regarded as God's sacrifice for the world's sin, does all this. The life and death of Jesus Christ, regarded in any other aspect, does not do this. Historically speaking: mutilated forms of Christianity, which have not known what to do with the Cross of Christ, have lost their constraining, purifying, and aggressive power. For us sinful men, if we are to be delivered from evil and become sons of God, He must suffer many things, and be killed, and rise again the third day.