Israel had a Book. It was only a fraction of what we now have in God’s Word, but oh how important! God’s solemn warning to Joshua, standing at the threshold of a gigantic task, was to be very careful to keep close to the words of that Book. Joshua listened and obeyed, and God honored him with phenomenal success. What a lesson for church leaders!
The danger is that we can ignore the bits of Scripture that make us feel uncomfortable and emphasize the bits that make us feel superior to others. The point is that we need to be diligent to be obedient to all of Scripture and seek to understand it and apply it to our lives.
We should not add to Scripture and fall into the error of the Pharisees, both modern and ancient. Nor should be subtract from Scripture and fall into the error of the main line denominations that have abandoned their belief and commitment to Scripture. We should rather be like the Bereans (Acts 17:10-11) who searched the Scriptures to conform their belief to what has been revealed. Their commitment to the Book was commended and we should follow their example.