Matthew 12:34-36
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.
Matthew 15:19
For out of the heart proceed wicked thoughts, murder, adultery, fornication, theft, perjury, impiety of speech.
Matthew 23:13
"But alas for you, Scribes and Pharisees, hypocrites, for you lock the door of the Kingdom of the Heavens against men; you yourselves do not enter, nor do you allow those to enter who are seeking to do so.
Acts 5:3-4
"Ananias," said Peter, "why has Satan taken possession of your heart, that you should try to deceive the Holy Spirit and dishonestly keep back part of the price paid you for this land?
Acts 8:21-22
No part or lot have you in this matter, for your heart is not right in God's sight.
James 1:14-15
But when a man is tempted, it is his own passions that carry him away and serve as a bait.
James 1:27
The religious service which is pure and stainless in the sight of our God and Father is to visit fatherless children and widowed women in their time of trouble, and to keep one's own self unspotted from the world.
James 3:5-6
In the same way the tongue is an insignificant part of the body, but it is immensely boastful. Remember how a mere spark may set a vast forest in flames.