Greatness in the kingdom has to do with the way the believing community exercises discipleship through the extravagant discipline of forgiveness.
The usual title of this passage as “reproving the sinner” or “exercising church discipline” ignores the clear sense indicated by what precedes and follows it in the disciples’ question about greatness in the kingdom and the A parable is a brief story with a setting, an action, and a result. A prominent aspect of Jesus' teaching was telling parables to illustrate something about the kingdom, or reign, of God. More of the lost sheep. Since it is the Father’s will that not one “little one” be lost to the kingdom, this new community of disciples (“church,” 18:15, 17) will exhaust all options in order to make sure that not one of its members is lost. The key center to this effort will be the exercise of tough and practical forgiving love. Once again (see 16:19) Jesus is the Messiah whose life, death, and resurrection are God's saving act for humanity More promises that this community has the authority to exercise this forgiveness (“binding” and “loosing”) and that this authority will be grounded in Jesus’ abiding and empowering presence (18:20; see 28:20).