Luke 17:6-106 And the Lord said, If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it should obey you.7 But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat?8 And will not rather say unto him, Make ready wherewith I may sup, and gird thyself, and serve me, till I have eaten and drunken; and afterward thou shalt eat and drink?9 Doth he thank that servant because he did the things that were commanded him? I trow not.10 So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.
Whatever we do to serve the Lord, we need to do it with a spirit of humility. Our service to Him is not to earn any favors from Him, or to somehow make Him owe us. Whether we do a lot or a little, it is never going to be enough to repay to Him what He paid on our behalf, let alone make Him indebted to us.
As servants of Christ, we are duty bound to do everything we can to serve Him. We are to use all of our resources in a way that brings glory and honor to Him, because we belong to Him. As soon as we finish one task of service, we should begin another. There is no break time, no day off, and no vacation from our service to Christ. He created us and knows what is best for us, and He will give us rest when He sees fit.
We are to put Him first in every aspect of our lives. Verse 8 tells us to gird ourselves and serve Him first. "Gird thyself" is about the same idea as the modern phrase, "roll up your sleeves," meaning to get prepared to work by getting every hindrance out of the way. Verse 9 tells us that our service for the Lord doesn't even merit His thanks. "Doth he thank that servant because he did the things that were commanded him? I trow not." According to Webster: "TROW, v.i. To believe; to trust; to think or suppose." "I trow not," then means, "I think not."
We don't have God's favor because He owes us for our service, but because He owes His own honor because of the promises He has made to us. Whether we do more or less than anyone else to serve God, we will never go above and beyond our duty to Him. Even those who have done the most, even to the point of sacrificing their lives for Him, must acknowledge that they are unprofitable servants according to verse 10. This is because all of our service does not add anything to God or make Him better. If it did, then He could become indebted to us and would cease to be supreme. Without us, God is still God, but without God, we are nothing.