The Missionary’s Greatest Duty is No Duty at All

Jesus knew his greatest duty and was set to complete it. Yet along the way to Jerusalem he stopped and gave attention to some of the worst of society—lepers (Luke 17:11–17). According to Old Testament Law, these ten would have been a good distance away from public spaces to avoid infecting others with their disease.

Normally, they would have shouted warnings of their disease to those passing by. This time, however, they shout desperations. To be sure, crying out to Jesus for mercy entailed some level of faith. Jesus acknowledged this, telling them to show themselves to the priest.

According to the Law, that was what they were supposed to do if they felt they had already been healed. The priest would then observe them and pronounce them clean if they were indeed healed (Lev. 14). So when the ten lepers obediently hightailed it to the priest, they believed to some extent that Jesus was able to heal them.

Along the way, they realized they had indeed been healed. R. Kent Hughes writes poignantly, “From cadaverous faces reemerged ears, noses, eyebrows, lashes, hairlines. Feet—toeless, ulcerated stubs—were suddenly whole, bursting shrunken sandals. Knobby appendages grew fingers. Barnacled skin became soft and supple. It was like ten new-births.”

A Life Of Compassion Is Marked with Suffering

But only one, a Samaritan, the worst among the worst, returned to thank Jesus. The other nine, all Jews, well, who knows? Maybe they continued on to the priest. After all, that was their ceremonial duty. Perhaps they did not return to Jesus in order to save face because they couldn’t repay him—an expectation in first-century Palestine’s culture of “you scratch my back and I’ll scratch yours.” But, more importantly, making their way to the priest complies with the theme of Luke 17 thus far, which illustrates the sad shortcomings of only doing one’s duty.

Motivated by Love

The Samaritan knew he had nothing to offer—and that was the whole point. He forsook duty to the law and went straight to the heart of the law: loving God. And Jesus’ response? “Rise and go your way; your faith has made you well(v. 19).

Luke used this broken man as a living example of what Jesus had been attempting to teach his disciples in Luke 17 about sin, faith, and duty (cf. vv 1–10). Faith and duty for faith and duty’s sake crumble in light of Jesus himself. In other words, “when [we] have done everything [we] were told to do, [we] should say, ‘We are unworthy servants; we have only done our duty’” (Luke 17:10, emphasis mine).

“An obsession with merely doing all that God commands may be the very thing that rules out being the kind of person that he calls us to be.”

I find in this passage so much relevance to missionary experience. A pastor’s recent comment about missionaries resonated with me: “Most missionaries I know are exhausted and working themselves to death . . . and we only applaud?” There are scary things lurking within our motivation toward God’s mission. Scarier still, however, is that pursuing missions is so admirable we may not even see them.

In Hearing God, Dallas Willard reflects on Luke 17. I remember shuddering as I read the climactic line: “An obsession with merely doing all that God commands may be the very thing that rules out being the kind of person that he calls us to be.”

It was as if he knew that, despite having good motivations, I had sworn myself to the cause of missions for the sake of fulfilling invisible should’s and ought’s. These were deep, wordless convictions that in time surfaced and spoke:

  • “If you really want to be a strong Christian, you should serve as a missionary.”
  • “Prove your salvation by sharing the gospel with everyone you encounter.”
  • “If you want to experience life like in the book of Acts, it is only possible overseas.”
  • “You ought to go into global missions because that’s how God will be most pleased with you.”

The Perfect Example

We might find these statements to be harmless, but in light of Luke 17, I encourage further inspection. Each bears enough hint of duty to be antithetical to the gospel of grace that was forged by the only missionary who perfectly fulfilled his duty. It is written of him:

Behold my servant, whom I uphold, my chosen, in whom my soul delights; I have put my Spirit upon him; he will bring forth justice to the nations. He will not cry aloud or lift up his voice, or make it heard in the street; a bruised reed he will not break, and a faintly burning wick he will not quench; he will faithfully bring forth justice. He will not grow faint or be discouraged till he has established justice on the earth; and the coastlands wait for his law (Isa. 42:1–4 ESV).

Where our faith is misguided, his was faithful. Where our service is selfish, his was sacrificial. Where our motives are disappointing, his were pleasing. And everything he demands, he supplies (Heb. 2:17).

So it’s right for us to run to him with our desires, ambitions, selfishness, and duty. His arms are open to those who accept that they can’t repay him, nor attain to biography-worthy missionary status. This is the missionary’s greatest duty and the only one that will keep them rising and going their way.


To explore opportunities to love others around the globe, visit our opportunities page.