'Heart' in the Bible

Because, knowing God, they glorified him not as God, neither were thankful; but fell into folly in their thoughts, and their heart without understanding was darkened:

but, according to thy hardness and impenitent heart, treasurest up to thyself wrath, in the day of wrath and revelation of the righteous judgment of God,

but he is a Jew who is so inwardly; and circumcision, of the heart, in spirit, not in letter; whose praise is not of men, but of God.

But thanks be to God, that ye were bondmen of sin, but have obeyed from the heart the form of teaching into which ye were instructed.

that I have great grief and uninterrupted pain in my heart,

Brethren, the delight of my own heart and my supplication which I address to God for them is for salvation.

But the righteousness of faith speaks thus: Do not say in thine heart, Who shall ascend to the heavens? that is, to bring Christ down;

But what says it? The word is near thee, in thy mouth and in thy heart: that is, the word of faith, which we preach:

that if thou shalt confess with thy mouth Jesus as Lord, and shalt believe in thine heart that God has raised him from among the dead, thou shalt be saved.

For with the heart is believed to righteousness; and with the mouth confession made to salvation.