A Christian's work in the local church is obligatory under Christ. In addition to the local church work, early Christians co-operated in work covering a large territory and scope; and formed a simple organization for this purpose (1 Cor. 16:3; 2 Cor. 8:18, 19, 23). This example shows that voluntary organization of individual Christians for general co-operative work is proper and Scriptural. Of this nature are missionary societies and benevolent associations which are formed to carry on general work, but have no ecclesiastical authority. _The Mission of the Church._ The mission of the church is to perpetuate and perfect itself and to add to its membership, through evangelization, the entire world as far and as fast as possible. The fundamental means adopted to carry out this mission is the church service. Our word _church_ is not derived from the New Testament word used in speaking of the body of believers, and it has a tendency to hide the real idea of the New Testament. It primarily refers to a church building, then to the body of believers worshiping in the building, and finally to believers in general. The inspired writers use the word _ekkleesia_, which means a gathering of people called from their homes into some public place. A correct translation would be _"assembly"_ or _"congregation,"_ as it has reference primarily to a local body of Christians assembled for work and worship. If this primary idea were restored, it would make mightily for the strengthening of Christ's kingdom. We usually put the emphasis on the church _in general, universal_ and _invisible,_ while the Holy Spirit puts the emphasis on the _local, visible_ and _tangible_ church. Our practical duties are connected almost entirely with the local church to which we belong and through which we chiefly help to build up the general and invisible church. The church is the assembled Christians first of all, and the first duty of Christians is to assemble (Heb. 10:25). For people to say that they belong to the church (assembly), who do not assemble or attend the church services, is an anomaly, strictly speaking.