Matthew 12:34-35
O vipers' brood, how can you speak what is good when you are evil? For it is from the overflow of the heart that the mouth speaks.
Luke 6:45
A good man from the good stored up in his heart brings out what is good; and an evil man from the evil stored up brings out what is evil; for from the overflow of his heart his mouth speaks.
Matthew 15:19
For out of the heart proceed wicked thoughts, murder, adultery, fornication, theft, perjury, impiety of speech.
Mark 7:21-23
For from within, out of men's hearts, their evil purposes proceed--fornication, theft, murder, adultery,
Mark 14:38
Be wakeful, all of you, and keep on praying, that you may not come into temptation: the spirit is right willing, but the body is frail."
Hebrews 12:15
Be carefully on your guard lest there be any one who falls back from the grace of God; lest any root bearing bitter fruit spring up and cause trouble among you, and through it the whole brotherhood be defiled;
James 1:14-15
But when a man is tempted, it is his own passions that carry him away and serve as a bait.