It is the cause for which Jesus left the throne of heaven. The heathen are His inheritance, given to Him by His Father. It is in heathendom that the power of Satan has been established. Jesus must have Himself vindicated as the conqueror. His glory, the coming and manifestation of His kingdom, depend on missions.
Missionary work is the principal aim of the church on earth.
All the last words of the Lord Jesus teach us this. He can do His work. It is the work for which the Holy Spirit was given. In the history of the Church we find that times of revival go hand in hand with new zeal for the missionary cause. The Holy Spirit is always a holy enthusiasm for the extension of the kingdom.