1. The unity of Christians is a vital unity. The members of the body of Christ form one whole because they partake of one common life. "By one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit." The unity of those who together form the body of Christ is not a mechanical unity, as of a pound of shot in a bag; nor is it a unity imposed by external force, as of caged wild beasts in a menagerie; nor is it a unity of mere accidental juxtaposition, as of passengers in a train or of the inhabitants of a town. But as the life of the human body maintains all the various members and nourishes them to a well-proportioned and harmonious growth, so is it in the body of Christ. Remove from the human body the life that supports it, and all the members fall away from connection with one another; but so long as the life is retained it assimilates in the most surprising way all nutriment to its own precise type and form. The lion and the tiger may eat precisely the same food, but that food nourishes in each a different form. The life that animates the human body assimilates nutriment to its own uses, imparting to each member its due proportion and maintaining all the members in their relation to one another. The unity of Christians is a unity of this kind, a vital unity. The same spiritual life exists in all Christians, derived from the same source, supplying them with similar energy, and prompting them to the same habits and aims. They accept the Spirit of Christ, and so are formed into one body, being no more isolated, self-seeking, and each man fighting for his own hand, but banded together for the promotion of one common cause. There is no clashing between the interests of the individual and the interests of the society or kingdom to which he belongs. The member finds its only life and function in the body. It is by the freest and most deliberate exercise of his reason and his will that a man attaches himself to Christ, seeing that by so doing he enters the only path to real happiness and attainment. The individual can only utter and fulfil his best self by doing his possible for society. His devotement to public interests is no self-destroying generosity, but the dictate of duty and of reason. To quote a writer who deals with this matter from the philosophical point of view, "he who has made the welfare of the race his aim has done so, not from a generous choice, but because he regards the pursuit of this welfare as his imperative duty. The welfare of the race is his own ideal, what he must realize in order to be what he _ought_ to be. The welfare of the race is his own welfare, which he must seek because he must be _himself_. Cromwell, Luther, Mahomet, were heroes, not because they did something over and above what they _ought_ to have done, but because their _ideal self_ was coextensive with the larger life of their world.