Every word of God is tested; He is a shield to those who take refuge in Him. Do not add to His words or He will reprove you, and you will be proved a liar (Proverbs 30:5-6).
Everything in the Word of God is intended to influence the heart and conduct. It is pure and trustworthy because it is God's Word, not man’s. It is sufficient; therefore, nothing needs to be added to it. All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness; so that the man of God may be adequate, equipped for every good work (2 Timothy 3:16-17).