Consequentially, you too must think of yourselves as (being) dead to sin and living for God in Christ Jesus. Rom 6 : 11

It's about the reward that awaits those who serve Him even indirectly. It's about those who show kindness towards those who serve Him, One becomes a sharer  to the rewards of a disciple.

The story of the rich couple. They welcomed prophet Elisha on his missionary tour. God rewards them for this deed. He promises them a child. The couple that welcomed the prophet who was passing  through their town on missionary tours. The childless couple showed kindness to a servant of God, a prophet and God rewarded  them with the promise of a child. This was the reward for being charitable towards a servant of God.

Christ became victorious by God's grace. But we all know how hard it was for Him to be victorious. His was a hard life on earth, full of sacrifices and suffering. In the end it was his death on the cross that gave Him the victory of the resurrection, a birth to a new life.

This same victory is assured to those who are baptized.  That is the reward given by God to those for becoming  His followers through baptism.  That is also the greatest gift that a man could receive.  It is given for being baptized. 

The Gospel places the disciples on an equal footing with Jesus. Thus we become sharers of the same gift as those who dedicated themselves to serve the Lord.

Those who have not taken up to direct preaching of the Good News as their mission, should understand that it is their responsibility to look after the needs of the servants of the Lord.   They should provide them with their daily needs, security and shelter. The satisfaction of a genuine servant of God is realized when one listens to the Good News and takes steps to change his sinful life. New life will be the greatest charitable act by which one could honour or entertain a servant of God, as Christ works unceasingly to change the sinful ways of man. He is committed to that; it is for this that He gives His life. Therefore, the greatest act of charity one could do is to listen to Christ's  message and change our sinful life. Whoever does this will be rewarded with the greatest gift; that of union with God.