Let us muse from Colossians 3:22b and the way we are to serve our employer. Paul says for us to serve not because of eye service. The idea is we should work just as hard when the boss is watching as when he is not watching. Our work should never be done because the boss  is watching but because God is watching. Paul says we do it with singleness of heart. The phrase means sincerely and heartily as to the Lord. When we go to work we are not working for our employer, but we the people of God work for the Lord.