The word for servant in this verse means 'slave' or even 'bond slave.' Almost like slavery we Christians are bought with a price (1 Cor. 6:20). However, in contrast to slavery, we serve a wonderful Lord and Savior, not a taskmaster at all. Jesus does not 'crack the whip' nor mistreats us, rather He sent us another Comforter to aid us in our daily lives to become the kind of Christian we ought to be (i.e. more Christ-like).
Another term describing Christians is 'saints.' That means we are 'set apart.' But we are not merely set apart to do nothing. We are set apart for the purpose of serving God. I used to belong to a church where people had to go through a process before being called a saint. But Biblically speaking, a saved person is a saint. This means that all who claim to know Jesus Christ as Lord and Savior have a responsibility to serve. We are saved to serve. Many today like the 'saving' part but do not want anything to do with the 'serving' part. I don't know if that kind of an attitude is becoming of a saint. Not that serving merits Salvation, but rather Salvation produces servitude.