Missions is not the ultimate goal of the church. Worship is. Missions exists because worship doesn't. Worship is ultimate, not missions, because God is ultimate, not man. When this age is over, and the countless millions of the redeemed fall on their faces before the throne of God, missions will be no more. It is a temporary necessity. But worship abides forever.
Worship therefore, is the fuel and goal in missions. It's the goal of missions because in missions we simply aim to bring the nations into the white-hot enjoyment of God's glory. The goal of missions is the gladness of the peoples in the greatness of God. 'The Lord reigns; let the earth rejoice; let the many coastlands be glad! (Psalm 97:1). Let the peoples praise thee, O God; let all the peoples praise thee! Let the nations be glad and sing for joy! (Psalm 67:3-4).
But worship is also the fuel of missions. Passion for God in worship precedes the offer of God in preaching. You can't commmend what you don't cherish. Missionaries will never call out, 'Let the nations be glad!', who can't say from the heart, 'I rejoice in the Lord...I will be glad and exult in thee, I will sing praise to thy name, O Most High' (Psalm 104:34;9:2). Missions begins and ends in worship.- From Let the Nations be Glad by John Piper