Luke 17:7-10
"Suppose one of you had a servant plowing or looking after the sheep. Would he say to the servant when he comes in from the field, 'Come along now and sit down to eat'? Would he not rather say, 'Prepare my supper, get yourself ready and wait on me while I eat and drink; after that you may eat and drink'? Would he thank the servant because he did what he was told to do? So you also, when you have done everything you were told to do, should say, 'We are unworthy servants; we have only done our duty.'