Matthew 12:34-36
You brood of vipers! How can you, wicked as you are, say anything that is good? For the mouth talks about the things that fill the heart.
Matthew 15:19
For out of the heart come evil thoughts, murder, adultery, immorality, stealing, false witnessing, irreverent speech.
Matthew 23:13
"A curse on you, you hypocritical scribes and Pharisees! For you bolt the doors of the kingdom of heaven in men's faces, for you neither go in yourselves, nor do you let those who are trying to do so go in.
Acts 5:3-4
And Peter said, "Ananias, why has Satan so completely possessed your heart that you have lied to the Holy Spirit and kept back for yourselves a part of the money received for the land?
Acts 8:21-22
You have no share or part in this matter, for your heart is not sincere in the sight of God.
James 1:14-15
But anyone is tempted to do evil when he is allured by his own evil desire and enticed by a bait.
James 1:27
A religious worship that is pure and stainless in the sight of God the Father is this: To look after orphans and widows in their trouble, and to keep one's own self unstained by the world.
James 3:5-6
So the tongue, too, is a little organ but can boast of great achievements. See how a spark, ever so tiny, can set a vast forest on fire!