In chapter 2, Peter is teaching us a great deal about false teachers, and the development of that teaching continues into verses 10b-16. In verses 15-16 Peter compares them to Balaam. The big idea in this passage is that there are some Christians who, if they don’t get you abandon Christ through bad teaching, they get you through bad living. We must not accept as normal those who call themselves Christians but reject the Christian way of living. These kinds of “Christians” are dangerous.