Thus we find the Apostle adducing the marriage tie, the highest earthly example of union, founded on choice and affection. But even that sacred bond leaves a gap between those who are knit together by it; and so we have the conception of our text, the unity of the body as representing for us the unity of believers with Jesus. This is a unity of life. He is not only head as chief and sovereign, but He is soul or life, which has its seat, not in this or that organ as old physics teach, but pervades the whole and 'filleth all in all.' The mystery which concerns the union of soul and body, and enshrouds the nature of physical life, is part of the felicity of this symbol in its Christian application. That commonest of all things, the mysterious force which makes matter live and glow under spiritual emotion, and changes the vibrations of a nerve, or the undulations of the grey brain, into hope and love and faith, eludes the scalpel and the microscope. Of man in his complex nature it is true that 'clouds and darkness are round about him,' and we may expect an equally solemn mystery to rest upon that which makes out of separate individuals one living body, animated with the life and moved by the Spirit of the indwelling Christ. We can get no further back, and dig no deeper down, than His own words, 'I am ... the life.' But, though this unity is mysterious, it is most real. Every Christian soul receives from Christ the life of Christ. There is a real implantation of a higher nature which has nothing to do with sin and is alien from death. There is a true regeneration which is supernatural, and which makes all who possess it one, in the measure of their possession, as truly as all the leaves on a tree are one because fed by the same sap, or all the members in the natural body are one, because nourished by the same blood. So the true bond of Christian unity lies in the common participation of the one Lord, and the real Christian unity is a unity of derived life. The misery and sin of the Christian Church have been, and are, that it has sought to substitute other bonds of unity. The whole weary history of the divisions and alienations between Christians has surely sufficiently, and more than sufficiently, shown the failure of the attempts to base Christian oneness upon uniformity of opinion, or of ritual, or of purpose. The difference between the real unity, and these spurious attempts after it, is the difference between bundles of faggots, dead and held together by a cord, and a living tree lifting its multitudinous foliage towards the heavens. The bundle of faggots may be held together in some sort of imperfect union, but is no exhibition of unity. If visible churches must be based on some kind of agreement, they can never cover the same ground as that of 'the body of Christ.'