The idea of a Kingdom implies the necessity of unity. And it was provided that the essential unity of "The Kingdom of Heaven" should be maintained through the Headship of the one King over all. The King commissioned His Apostles to make all the nations of the world His subjects, and assured them of the authority to do this by promising to be with them and their successors to the end of the world. And wherever the Church spread, however defective and imperfect it might be, it was still part of one and the same Kingdom, owning the Lord Jesus Christ as King. Besides this bond of union, one Holy Spirit was working with more or less success upon all the subjects, wherever they might be; one Hope was held out before all, of salvation; one Faith in the ever-blessed Trinity was taught to all, and professed by all; one Baptism enrolled all; one God was the object of the worship of all. But the unity of a Kingdom depends not only upon the King and the laws and ordinances of the Kingdom, but also upon the loyal obedience of the subjects. And the subjects of "The Kingdom of Heaven" have, in past times, so far forgotten this duty, that it has come to pass that for centuries the great branches of the Church of Christ have had little, if any, outward communion or fellowship with one another. And in our own country the professed members of Christ are divided into many bodies, not only independent of one another, but oftentimes opposing, rather than helping forward, the extension and well-being of the Kingdom of our Lord and Saviour Jesus Christ. And the result has been that we have learned by sad experience the reason of the foreboding tone of our Lord's last prayer, "That they all may be one; ... that the world may believe that Thou hast sent Me" (S. John xvii. 21). The multitudes of men, practically heathen, in the midst of this professedly Christian land, and the still greater multitudes of men in other lands whom the good news of the Kingdom has not reached, are proofs of the weakness of the Church of Christ. Christians are not "one;" and consequently "the world" does not "believe" in Him whom the Father of His great love sent to be its Saviour.