"If any man thinketh himself to be religious, while he bridleth not his tongue but deceiveth his heart, this man's religion is vain."
"When men take more pains to seem religious than really to be so, it is a sign their religion is in vain. The not bridling the tongue, readiness to speak of the faults of others, or to lessen their wisdom and piety, are signs of a vain religion. The man (or woman) who has a slandering tongue, cannot have a truly humble, gracious heart..." Matthew Henry
slander: the action or crime of making a false spoken statement damaging to a person's reputation.