There is great danger of losing sight of the Church in the endeavor to emphasize the idea of the Kingdom of Heaven or Christendom. We are prone to think it a small thing to speak of the Church; the Kingdom and Christendom seem so large in comparison. We are tempted to distinguish and contrast Churchism, as it is sometimes called, and Christianity, to the disparagement of the former. It is well to remember that Jesus Christ positively identifies Himself with the Church (Acts 9) and not with Christendom; He gave up His life that He might found the Church (Eph. 5:25). The Apostle Paul sacrificed himself in his endeavors to build up the Church, not Christendom. He speaks of his greatest sin as consisting in persecuting the Church of God (1 Cor. 15:9). The supreme business of God in this age is the gathering of the Church. Some day it will be complete (Eph. 4:12), and then the age will have served its purpose. I. DEFINITIONS; DISTINCTIONS. 1. OLD TESTAMENT USE OF THE WORD. Lev. 4:13--"And if the whole congregation of Israel sin through ignorance, and the thing be hid from the eyes of the assembly . . . ." The Hebrew word for _assembly_ means to _call_ or _assemble,_ and is used not only for the act of calling itself, but also for the assembly of the called ones. In this sense Israel is called a "church," an assembly, because called out from among the other nations to be a holy people (Acts 7:38, "the church in the wilderness"). There is always a religious aspect associated with this particular call. 2. THE NEW TESTAMENT USE OF THE WORD. It is from the New Testament primarily, if not really exclusively, that the real meaning and idea of the Church is derived. The Christian Church is a New Testament institution, beginning with Pentecost, and ending, probably, with the rapture. Two words are of special importance in this connection: a) Ecclesia, from Two Greek Words Meaning "To Call Out From." This word is used in all about 111 times in the New Testament. It is used in a secular sense in Acts 19:39--"It shall be determined in a lawful assembly"; of Israel in the wilderness (Acts 7:38), and of the assembly of believers in Christ (Matt. 16:18; 18:17; 1 Cor. 1:2; Eph. 5:25-27). In keeping with this idea the saints are said to be the "called-out" ones (Rom. 8:30; 1 Cor. 1:2; cf. 2 Cor. 6:17). b) "Kuriakon"--That Which Belongs to the Lord. So we have "the supper of the Lord" (1 Cor. 11:20); the "day of the Lord" (Rev. 1:10). See also Luke 22:25 and Rom. 14:8, 9, as illustrating that over which the Lord has dominion and authority. To sum up then: The Church is composed of the body of believers who have been called out from the world, and who are under the dominion and authority of Jesus Christ. c) The Growth of the Church Idea in the New Testament.