The key to the missionary’s work is the authority of Jesus Christ, not the needs of the lost.
It puts our service to God in the right perspective, I believe. If we serve people, we are tempted to loose sight of the Sovereign and He Who is truly worthy of our time and worship. If we rightly and properly serve God at all times in all activities, we will find ourselves loving and serving His creation.
Perspective is everything when it comes to relevance.