The reason that this unity is necessary is stated in the prayer of Jesus, "that they all may believe that thou hast sent me."

John 17:21 that all of them may be one, Father, just as you are in me and I am in you. May they also be in us so that the world may believe that you have sent me.

The salvation of the world by the preaching of the gospel is the task of Christ and his church. The accomplishing of this goal has been hindered by division into many denominations and sects. Such division wastes time, energy, money and confuses those who seek for truth. The world can not be won till the followers of Christ are one.