Verse 9 is an interesting verse because it reminds us that we do not have to engage in endless debate with people who will not listen. Some people are so set in their ways and hard-hearted that the truth has no appeal to them. It can be exhausting to continue to try to teach someone the truth of the Scripture when they simply want to argue and will not truly listen. Even Jesus gave his disciples the option to walk away from people who won't hear the truth. He told them go and give people a chance to hear, but if they reject it and don't want to hear it you can wipe the dust from your feet and walk away.
We should give our attention to seekers who are open to the Gospel. This doesn't mean they accept it right away, but if they are open and asking questions, we keep the conversation going. It may take a while for them to accept the truth, and some may never get there, but at least they are open. Others who are hostile, mocking, or simply want to argue without listening can cause us massive discouragement and distraction from telling those who want to hear what we have to say. If we give someone a chance to hear the truth and they don't want to hear it, we don't have to sit there and argue with them endlessly; we can move our attention to someone who wants to hear. We can't let the negative reactions of some keep the Gospel from others who need to hear it. Don't let one bad experience or one frustrating person silence you from speaking the truth when so many people are desperately seeking hope.