The rest of chapter 9 (verses 36 through 50) continues the conversation that Jesus was having with his disciples. He touches on several subjects at the same time and yet he ties it all together somehow.
Jesus begins by holding a child, and talking of caring for them. I think he could be talking of new Christians as well. Take them into your care.
Then John spoke of one who was not a follower but was casting out devils. He and the other disciples stopped him. Jesus told him not to stop someone like that. No one who does good will speak evil of Jesus. I think Jesus is speaking of new Christians and those who are trying to live a Christian life. Be careful how you treat them. Teach, but don't offend them. Children are precious; anyone who would deliberately hurt a child, we think should be punished. Babes in Christ are the same as children. Anyone who would deliberately do something to hurt them spiritually, Jesus said it is better that a millstone is hung around that person's neck and cast into the sea (v42).
Jesus continues his speech by talking of temptations and offenses. If your right eye causes you to sin, cast it out. It's better for you to have one eye than to keep both eyes and end up in hell (Gehenna). Look for the cause of the problem, he is saying. In today's terms, get rid of the temptation. In the movie Fireproof from a few years back, starring Kirk Cameron, the young man in the story had an addiction --a sin, to put it more bluntly -- to pornography. He could easily find it on the internet. That and other problems were tearing his marriage apart. While the movie teaches nothing about baptism as a part of salvation, it focuses on the sanctity of marriage and a relationship with Christ. As the young man studies more and realizes what he is doing, he decides to destroy the computer at home. He got rid of the source of the sin.
I leave with you verse 50, which I think ties together the conversation.
50. Salt is good: but if the salt have lost his saltness, wherewith shall ye season it? Have salt in yourselves, and have peace with one another.