Contradiction with Proverbs 3:5
Trusting in the LORD rather than in one's own spoken beliefs contradicts the notion of speaking because of belief.
Proverbs 3:5: Trust in the LORD with all thine heart; and lean not unto thine own understanding.
Contradiction with Ecclesiastes 5:2
Advises against being hasty with words or speaking impulsively which contrasts with speaking out as a result of belief.
Ecclesiastes 5:2: Be not rash with thy mouth, and let not thine heart be hasty to utter [any] thing before God: for God [is] in heaven, and thou upon earth: therefore let thy words be few. [thing: or, word]
Contradiction with James 1:19
Encourages being slow to speak, which can contrast with the speaking boldness suggested by faith in 2 Corinthians 4:13.
James 1:19: Wherefore, my beloved brethren, let every man be swift to hear, slow to speak, slow to wrath:
Contradiction with Job 6:24
Job desires to be taught and corrected in understanding, implying restraint in speech, as opposed to speaking from belief.
Job 6:24: Teach me, and I will hold my tongue: and cause me to understand wherein I have erred.