God is more interested in our sanctification than He is in our service. Let us get that clear. It explains much else, including many of our apparent failures. No God-sent missionary who believes in Jesus Christ is allowed to call himself a failure!
This does not mean that a missionary is a special breed of Christian. To change from his native land and culture to another does not place a halo on the head of the Christian worker. No one knows that better than the missionary himself. If others make that mistake he is not likely to do so.
What I mean is this. In speaking of success and failure we are right at the heart of what being a Christian is all about. God is determined to save His people in the fullest sense of that term. Salvation means a great deal more than to keep a sinner out of hell!
And then later in the same chapter.
But there is a broader view. It is this: God's team is the winning team. Never mind the setbacks. They will come. But as surely as God is God, His team is the winning team. In the most discouraing place on earth and at the most disheartening hour, the cause is never in doubt. Of what other cause can this be said? None on this earth; not one! The missionary is engaged in this world's only sure pursuit. Let him take heart. His resolve can never be in vain. He serves the royal Master, the victorious Prince.
This dude is on fire.
Both quotes are by Tom Wells from A Vision for Missions.