Jeremiah 17:1

Do not let lovingkindness and truth forsake you; Bind them around your neck, Write them on the tablet of your heart.

And they do not say to their hearts That I remember all their evil. Now their deeds are all around them; They are before My face.

“And they made their hearts diamond-hard so that they could not hear the law and the words which Yahweh of hosts had sent by His Spirit by the hand of the former prophets; therefore great wrath came from Yahweh of hosts.

being manifested that you are a letter of Christ, ministered to by us, having been written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of hearts of flesh.

The Deceitful Heart