Matthew 12:34
How can ye, evil as ye are, speak good things? For out of the abundance of the heart the mouth speaketh.
Romans 3:13-14
Their throat is an open sepulchre; with their tongues they have practised deceit. The poison of asps is under their lips.
2 Corinthians 11:3
but I fear, lest by any means, as the serpent beguiled Eve by his subtlety, so your minds should be corrupted from singleheartedness toward Christ.
James 3:6-8
And the tongue is a fire, a world of iniquity! The tongue among our members is that which defileth the whole body, and setteth on fire the wheel of life, and is itself set on fire by hell.