Verse 6 talks about the special relationship people have with their grandchildren. I don't have grandchildren, but I have heard from many people who do how wonderful that relationship is. I also know from experience that grandparents can have a tremendous impact on the lives of their grandchildren. Grandparents serve an important role in the spiritual development of their grandchildren.
Verse 9 is addressing the issue of gossip. When we know someone has made a mistake or sinned the best thing we can do is keep the circle as tight as possible in addressing the issue. Obviously, sometimes we need to bring in help if we are dealing with a very serious situation. For most things though we can keep what we know in confidence. It is not up for us to tell everyone about the issues of another. Rather we are good at keeping things between us. This is how you build confidence with another person. So many people struggle alone because they fear that if they open up about their problem it will become public knowledge. We all need people that we know we can simply trust to keep things in confidence and help us through.
The other part of this is also if someone offends us or makes us mad. It is the idea of can I let it go or if it needs to be dealt with can I go directly to the person and deal with it one-on-one. The worst thing we can do with an offense or a problem with someone is to take it to everyone else and vent. Rather than solve a problem it just makes things worse. In community- like church or friendship it will start dividing people and split friendships as people feel the need to pick sides. As much as we can we need to take insult and offense and lay at the feet of God to deal with rather than the ears of everyone around us.