'Heart' in the Bible

Or is it nothing to you that God had pity on you, waiting and putting up with you for so long, not seeing that in his pity God's desire is to give you a change of heart?

But by your hard and unchanged heart you are storing up wrath for yourself in the day of the revelation of God's judging in righteousness;

But he is a Jew who is a secret one, whose circumcision is of the heart, in the spirit and not in the letter; whose praise is not from men, but from God.

In my heart I take pleasure in the law of God,

So then, at his pleasure he has mercy on a man, and at his pleasure he makes the heart hard.

But the righteousness which is of faith says these words, Say not in your heart, Who will go up to heaven? (that is, to make Christ come down:)

But what does it say? The word is near you, in your mouth and in your heart: that is, the word of faith of which we are the preachers:

Because, if you say with your mouth that Jesus is Lord, and have faith in your heart that God has made him come back from the dead, you will have salvation:

For with the heart man has faith to get righteousness, and with the mouth he says that Jesus is Lord to get salvation.