This short section highlights four aspects of discipleship. It is hard to be certain if these four characteristics are simply listed or whether there is some relationship between them. If a relationship exists, a warning about sin and false teaching serves as a contrast to more positive exhortations about showing forgiveness, having faith and serving without demanding a reward. Faith understands forgiveness and leads to duty. In all these exhortations there is awareness of community. Christianity is not a privatized experience of faith.

Christianity is not a private affair, but a family one. Luke 17:1-10 is about our familial responsibilities. In America controversies are often framed in terms of the individual and his or her rights; but that is not the scriptural picture of how we relate to one another. Our text makes it clear that no Christian is an island unto himself or herself. We have responsibilities to each other. Unlike Archie Bunker of All in the Family, we should not see things only in terms of how they impact us. Service is not selfishness.

The first aspect of discipleship here is expressed in a warning not to be a cause of sin (vv. 1-3). It is inevitable that sin will come through false teaching. But woe to that person who brings it. The offense (skandalon) Jesus discusses here is probably serious sin that causes stumbling and a fall from faith. In the LXX this Greek term is used for the Hebrew concept of luring someone into a trap or of causing stumbling (Lev 19:14; Judg 8:27; 1 Sam 25:31; Ps 119:165; Stahlin 1971:344-47). The rhetorical picture of verse 2 indicates that serious sin is in view. Those who fail to come to Christ trip over the "scandal" of the cross (Is 8:14; Lk 20:18; Rom 9:33; 1 Pet 2:6-8). So the warning addresses teaching that leads to a loss of faith and a life of sin.

God's concern for his children is seen in Jesus' characterization of them as little ones. Caring for God's children is baby-sitting: the responsibility is great because the children are precious in their parents' sight. Children need attentive care. And teaching carries special responsibility (Jas 3:1).

In fact, those who lead others into error are at risk before God. So Jesus issues a warning: a Mafia-style death is better for the one who leads others into apostasy. Jesus pictures an execution with a concrete block tied around the necks of the condemned as they are cast into the sea. A millstone was a large, heavy stone used at the top of a grinding mill. It was a millstone that crushed Abimelech's head in Judges 9:53. The picture is of severe judgment. You are accountable, Jesus says, so watch yourselves. Be careful to avoid sin (Ps 141:8-10).

Family relationships require us to be responsible to be careful about sin and error. Jesus' stress here is that individuals must guard themselves in such matters. But the possibility of error needs to be balanced with forgiveness. So Jesus calls for rebuke for sin but also a quickness to forgive (vv. 3-4). The assumption behind such mutual accountability is the community's commitment to pursue righteousness (Gal 6:1). Jesus assumes that we encourage one another and honestly support one another's relationship with God. But the rebukes are personally directed, as they are personally experienced. Jesus is not suggesting that a kind of underground righteousness squad be appointed to watch for sin. Rather, when people wrong one another in the flow of relationships, they are to sort things out. That is why Jesus speaks of when someone sins against you (Mt 18:15-20; Gal 6:1; 1 Thess 5:14-15; 2 Thess 3:14-15; Tit 3:10-11). Sin should be rebuked, but repentance should be greeted with forgiveness. We should be quick to move on once the wrong is acknowledged. Just as there is a commitment to righteousness, so there is a commitment to restore relationships promptly. In Matthew 18:21, as here, the repetition of sinfulness does not preclude forgiveness. Whether seven times a day or seventy times seven, forgiveness is called for, since the goal is to restore relationships within the community. Such values existed in Judaism as well as in the church (Testament of Gad 6:3-5, 7; Rom 12:16-21).

Deep and honest relationships presuppose a grounding in relationship with God. So verses 5-10 deal with this other level of relationship. Sensitive to this linkage, the disciples ask for an increase in their faith. Jesus is concerned not about faith's volume but about its presence. God can work with even a little faith. So Jesus says, "If you have faith as small as a mustard seed, you can say to this mulberry tree, `Be uprooted and planted in the sea,' and it will obey you." The mustard seed was among the smallest seeds in Palestine (Michel 1965a:810-11; Mt 13:31-33), while the sycamine tree (Greek), probably a black mulberry tree, lived up to six hundred years. It required a vast root network to draw up the ground's nutrients. Jesus is arguing that a little faith can do surprising things, especially if merely through a spoken word it can pull up a tree with a huge root system and hurl it into the sea. Of course, the remark is a rhetorical picture of faith's power. It is like Jesus' remark about a camel's ability to go through the eye of a needle. It makes the point hyperbolically: do not fret about how great your faith is; only apply what you have and watch it work. The disciple's main responsibility is to trust God.

Out of such faith should come service. Jesus' final parable describes a servant (NIV), or more precisely a slave. "Slave" (doulos) was Paul's favorite self-characterization (Rom 1:1; also Lk 1:38; Jas 1:1). The service of God's servant is not a matter for negotiation but is a duty. The ancient household servant was responsible for many activities, from working the fields to preparing the meals. A ancient servant's work never seemed to be done. Such is also the case here. Jesus pictures a servant coming in from a long day of farming or shepherding, only to be asked to prepare the owner's dinner. The servant will not get a meal until the master is served. Not only that, the servant will not be thanked as if he had done something special. Rather, he will do it because it is his duty: "We are unworthy servants; we have only done our duty." This attitude is in sharp contrast with that of the Pharisee in 18:12. There is no selective obedience here, no bargaining to do something for the master if he does a favor in return. Our closest contemporary analogy to this obedience is the discipline of military life. Servants display humility (unworthy servants) and know their position. The servants of God know that God is not obligated to them, as if they were his equal, but they are obligated to him, because he is their Creator and Redeemer.

In the Jewish Mishna, 'Abot 2:7, a rabbi says, "If you have studied the Torah, do not claim merit for yourself, since you were created for this." The same is true of service for God. Committed service is a disciple's privilege.

So the disciple's life is lived in community with others and God. Be careful not to lead others into sin, Jesus says. When sin occurs, rebuke it, but be quick to forgive when there is repentance. Don't worry about having great faith; just let the faith you have do its surprising work. Finally, serve God as a matter of duty. If you trust God, you can serve him.