'Serves' in the Bible

With you it is not so; but let the greatest among you be as the younger, and the leader be like him who serves.

and whoever in this way devotedly serves Christ, God takes pleasure in him, and men highly commend him.

What soldier ever serves at his own cost? Who plants a vineyard and yet does not eat any of the grapes? Or who tends a herd of cattle and yet does not taste their milk?

Every one who serves as a soldier keeps himself from becoming entangled in the world's business--so that he may satisfy the officer who enlisted him.