The fundamental basis of all Christian missionary enterprise is the universal authority of Jesus Christ, “in heaven and on earth.” If the authority of Jesus were circumscribed on earth, if He were but one of many religious teachers, one of many Jewish prophets, and one of many divine incarnations, then we would have no mandate to present Him to the nations as the Lord and Savior of the world.
If the authority of Jesus were limited in heaven, if He has not decisively overthrown the principalities and powers, we might still proclaim Him to the nations, but we would never be able to “turn them from darkness to light, and from the power of Satan unto God” (Acts 26:18). Only because all authority on earth belongs to Christ do we dare go to all nations. And only because all authority in heaven as well is His do we have any hope of success.
– John Stott