If verbalization is important for us, as this would indicate, then His Word would tells us why. From Gen. cha. They confessed their lack of faith, and in vs. 28, after repeated confessions of this type, the Lord honored their confession. They didn't confess faith based upon God's promises, they confessed doubt based upon what their physical senses told them at the moment. These Scriptures point to the fact that there is a definite relationship between the words we speak and the condition of our soul.
Righteousness comes by faith.
A relationship between our faith, our speaking, and our soul is indicated. Confession, or verbalization which is contrary to God's Word can ultimately be detrimental to the salvation of our very souls. Verbalization in line with God's Word is an indication of our faith. David realized that our words can condemn us. Therein we are told that no man can tame the tongue.