Why is it important to know what's not in the Bible?
Knowing what is not in Scripture is important because anything essential to Christian practice is in the Book; if a practice cannot be found there, it must be wrong and puts a person on thin ice. It guards against deception, since a deceiver can appear to promote Scripture and lead many astray.
Les teaches that it is just as important to realize what is not in the Bible as to know what is in it, because many people go through life thinking something is in the Book simply because they heard it somewhere. He explains that the Lord has given the Holy Spirit, a mind, and intelligence so that by searching the Scriptures we can sort out false teaching. A lady asked for verses showing a certain practice was wrong; Les replied that he could not do that, but asked her to find a verse instructing people to do it. When it cannot be found and is not in the Book, it must be wrong, because anything part and parcel of the Christian walk is in the Book. If it is not in the Book, look out, you are on thin ice.