And the apostles said to the Lord, Give us more faith. So the Lord said, If you have faith as a mustard seed, you might say to this sycamine tree, Be pulled up by the roots and be planted in the sea, and it would obey you. But which of you, having a servant plowing or tending sheep, will say to him when he has come in from the field, Come, sit down to eat? But will he not rather say to him, Prepare something for my supper, and gird yourself and serve me till I have eaten and drunk, and afterward you will eat and drink? Does he thank that servant because he did the things that were commanded him? I think not. So likewise you, when you have done all those things which you are commanded, say, We are unprofitable servants. We have done what was our duty to do.

– Luke 17:5-10 (VW)

Does this passage appear confusing to you? What do unprofitable servants have to do with the apostle’s request for more faith? The one seems totally unrelated to the other. But there is a connection, and the answer begins with finding the common theme in what Jesus said.

After the disciples asked for more faith, Jesus spoke about faith. But He didn’t tell them how to obtain what they wanted. He only described what true faith would allow them to do. If they had the tiniest amount of that kind of faith, they would be able to command a tree to pluck itself up by the roots and plant itself in the sea. I would think my faith very strong if I had a faith like that. But Jesus said that is the smallest kind of faith.

Then Jesus appeared to change the subject without answering their question. He spoke about the working relationship between a slave and his master, which relationship the disciples were familiar with. A slave puts his master’s interests before his own. Only after the master’s needs are satisfied are the slave’s needs satisfied. This is a slave’s duty, and he is never commended for doing his duty. Such a slave only does what is expected of him.

What is the common theme? It doesn’t take much thought to see that the theme is obedience. The tree obeys the apostle, and the slave obeys his master. Obedience is what ties the two illustrations together. But it is not just any kind of obedience: it is heartless obedience. If you have enough faith to command a tree to plant itself in the sea and it obeyed you, you wouldn’t thank the tree for doing so. It merely did what you commanded it. Likewise, the unprofitable slave who does only what he is commanded to do has no reason to expect thanks from his master because his heart is not in it. If he were given an employee evaluation, it would be mediocre at best. But what do these illustrations have to do with acquiring faith? Much.

For one thing, although it’s easy to read it that way, Jesus is not telling us to give up hope of ever being anything more than unprofitable slaves ¹. He is not trying to discourage us. On the contrary, He wants us to be profitable slaves, but that doesn’t come about the way most of us think

We Christians tend to serve Jesus Christ out of a sense of duty. To be sure, there are some things He requires of us, such as continuing to forgive those who sin against us (Luke 17:3-4). But in serving our Lord, we shouldn’t seek to do the minimum required of us. If we love Him and trust Him, our love and trust will lead us to go beyond this.

After he was saved, Paul’s life revolved around sharing the gospel with everyone. Jesus had saved him for this very purpose; it was his duty. But Paul didn’t just do his duty…

…Do you not know that those who minister the holy things eat of the things of the temple, and those who serve at the altar partake of the altar? Even so the Lord has commanded that those who preach the gospel should live from the gospel. But I have used none of these things, nor have I written these things that it should be done so with me; for it would be better for me to die than that anyone should make my exulting void. For if I preach the gospel, there is no glory to me, for necessity is laid upon me; yes, woe is me if I do not preach the gospel. For if I do this willingly, I have a reward; but if against my will, I have been entrusted with a stewardship. What is my reward then? That when I preach the gospel, I may present the gospel of Christ without charge, that I may not abuse my authority in the gospel. For though I am free from all men, I have made myself a servant to all, that I might gain the more;

– 1 Corinthians 9:13-19

Paul’s mission was sharing the gospel with the gentiles. But his reward would not come merely from doing this, for that was his calling, his duty. He had no expectation of thanks for doing his duty (compare verse 16 with Luke 17:9). Instead, Paul expected a reward because he went beyond his duty by not taking advantage of his right to live off the gospel. Paul had this right, but he didn’t use it so that his mission would be more effective. To support himself, he also made tents ². This is where faith came in, because even though Jesus commanded evangelists to live off the gospel, he expected Jesus to reward him for presenting the gospel freely.

Other believers have also gone above and beyond the call of duty. Some Christians in the early church sold themselves into slavery to reach lost slaves for Jesus. It happened again among the 18th century Moravians. On August 21, 1732, Johann Leonhard Dober and David Nitschmann sailed from Copenhagen to the Dutch West Indies to sell themselves into a lifetime of slavery to reach the lost African slaves for Jesus. Others followed, many of which died of tropical illnesses. These people served Christ in faith, and many came to salvation because they went beyond the call of duty.

If you want more faith, even as small as a grain of mustard seed, don’t just do your duty: give all of yourself.

Do you not know that those who run in a race all run, but one receives the prize? Run in such a way that you may obtain it. …

– 1 Corinthians 9:24