The distinction between the servile spirit and the spirit of sonship being thus radical, it could be by no mere formality, or exhibition of his legal title, that Isaac became the heir of God's heritage. His sacrifice on Moriah was the requisite condition of his succession to Abraham's place; it was the only suitable celebration of his majority. Abraham himself had been able to enter into covenant with God only by sacrifice; and sacrifice not of a dead and external kind, but vivified by an actual surrender of himself to God, and by so true a perception of God's holiness and requirements, that he was in a horror of great darkness. By no other process can any of his heirs succeed to the inheritance. A true resignation of self, in whatever outward form this resignation may appear, is required that we may become one with God in His holy purposes and in His eternal blessedness. There could be no doubt that Abraham had found a true heir, when Isaac laid himself on the altar and steadied his heart to receive the knife. Dearer to God, and of immeasurably greater value than any service, was this surrender of himself into the hand of his Father and his God. In this was promise of all service and all loving fellowship. "Precious in the sight of the Lord is the death of His saints. O Lord, truly I am Thy servant; I am Thy servant, the son of Thine handmaid: Thou hast loosed my bonds."
So incomparable with the most distinguished service did this sacrifice of Isaac's self appear, that the record of his active life seems to have had no interest to his contemporaries or successors. There was but this one thing to say of him. No more seemed needful. The sacrifice was indeed great, and worthy of commemoration. No act could so conclusively have shown that Isaac was thoroughly at one with God. He had much to live for; from his birth there hovered around him interests and hopes of the most exciting and flattering nature; a new kind of glory such as had not yet been attained on earth was to be attained, or, at any rate, approached in him. This glory was certain to be realised, being guaranteed by God's promise, so that his hopes might launch out in the boldest confidence and give him the aspect and bearing of a king; while it was uncertain in the time and manner of its realisation, so that the most attractive mystery hung around his future. Plainly his was a life worth entering on and living through; a life fit to engage and absorb a man's whole desire, interest, and effort; a life such as might well make a man gird himself and resolve to play the man throughout, that so each part of it might reveal its secret to him, and that none of its wonder might be lost. It was a life which, above all others, seemed worth protecting from all injury and risk, and for which, no doubt, not a few of the home-born servants in the patriarchal encampment would have gladly ventured their own. There have, indeed, been few, if any, lives of which it could so truly be said, The world cannot do without this--at all hazards and costs this must be cherished. And all this must have been even more obvious to its owner than to any one else, and must have begotten in him an unquestioning assurance, that he at least had a charmed life, and would live and see good days. Yet with whatever shock the command of God came upon him, there is no word of doubt or remonstrance or rebellion. He gave his life to Him who had first given it to him. And thus yielding himself to God, he entered into the inheritance, and became worthy to stand to all time the representative heir of God, as Abraham by his faith had become the father of the faithful.