1 He said to his disciples, “Things that cause sin will inevitably occur, but woe to the person through whom they occur. 2 It would be better for him if a millstone were put around his neck and he be thrown into the sea than for him to cause one of these little ones to sin. 3 Be on your guard! If your brother sins, rebuke him; and if he repents, forgive him. 4 And if he wrongs you seven times in one day and returns to you seven times saying, ‘I am sorry,’ you should forgive him.”
[The Sunday reading begins here] 5 And the apostles said to the Lord, “Increase our faith.” 6 The Lord replied, “If you have faith the size of a mustard seed, you would say to (this) mulberry tree, ‘Be uprooted and planted in the sea,’ and it would obey you. 7 “Who among you would say to your servant who has just come in from plowing or tending sheep in the field, ‘Come here immediately and take your place at table’? 8 Would he not rather say to him, ‘Prepare something for me to eat. Put on your apron and wait on me while I eat and drink. You may eat and drink when I am finished’? 9 Is he grateful to that servant because he did what was commanded? 10 So should it be with you. When you have done all you have been commanded, say, ‘We are unprofitable servants; we have done what we were obliged to do.’”
Throughout the previous chapter (Luke 16), Jesus has addressed the Pharisees and scribes (scholars of the law) with beginning and ending parables: the dishonest steward and the rich man and Lazarus – each begins with a statement, “There was a rich man.” The clear target was the lovers of money, i.e., those whose love of riches prevented them from truly being lovers of God. Although the parable is aimed at the Pharisees the lesson continues a theme of 12:1 “Beware of the leaven–that is, the hypocrisy–of the Pharisees.” The disciples are reminded of the characteristics of true discipleship and well as the pitfalls along the way.
In addition, looking ahead to Luke 17:11: “As Jesus continued his journey to Jerusalem…” it is clear that Luke will return to a travel motif to tell the narrative. It is as though v.11 marks a new subsection within the longer travel narrative (9:51-19:48). Joel Green holds that 17:1-10 marks the end of lengthy question that began in 13:10, namely, “who will participate in the kingdom of God?” (Green, Luke, 611). If this is true, then clearly there two characteristics emphasized are faith and service.
In Luke 17 the audience for the lesson is the disciples (v.1). Luke draws together four sayings:
- a warning against causing others to stumble (vv.1-2), 
- a challenge to be forgiving (vv.4-5), 
- a call to the exercise of faith (vv.5-10) , and
- a reminder of the duties of discipleship (vv.11-19; next Sunday’s gospel) 
They seem to be disparate sayings, almost as thought thrown together, lacking a thematic coherence. But in the broader question of “who will participate in the kingdom of God?” the coherence may be as simple as “don’t be like the Pharisees” especially in their lack of regard of the “little ones” (v.2).
 See parallels in Matthew 18:6-7 and Mark 9:42
 See parallel in Matthew 18:15
 vv.5-6 are paralleled in Matthew 17:20. Luke 17:7-10 are unique to Luke
 Unique to Luke