““Either make the tree good and its fruit good, or else make the tree bad and its fruit bad; for a tree is known by its fruit. Brood of vipers! How can you, being evil, speak good things? For out of the abundance of the heart the mouth speaks. A good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things. But I say to you that for every idle word men may speak, they will give account of it in the day of judgment. For by your words you will be justified, and by your words you will be condemned.””
Matthew 12:33-37 NKJV
http://bible.com/114/mat.12.33-37.nkjv 