It is very interesting to note that Paul is describing how every employee should work in any job, because we are actually not just working, but we are also worshipping and we are witnessing. You see, your work and how you do it is an act of worship to God, because you are really working for him. It is a witness to others who are watching how Christians perform.
It may sound contradictory, but we really do believe in a God who is unbelievable and in this magnificent book, Paul tells us that what God has done for his people is unbelievable and what God wants to do through his people is unbelievable. God has taken the lowliest of the low and raised them to the highest of the heights. Just as in the beginning, God created something out of nothing. God in his magnificent grace claimed that which was lost, raised that which was dead, redeemed that which was enslaved, restore that which was broken and reconciled that which was separated.