The best defense, of course, is a good offense. But there are some other things we can do. We can remember some simple principles, Not everyone who sounds like an expert is an expert. These people are constantly being called upon to testify on all kinds of issues. There will always be people who talk authoritatively about God's will but have no idea what the Bible says.
Many people engage their mouth well before they engage their brain.
People merely parrot what they have heard others say. Some have never considered the implications of their words. Something that sounds good is not necessarily something that IS good. Most deception comes in brightly colored packages. We must see beyond the polished words and slick presentation.