'Heart' in the Bible

He who professes to know Him, and yet does not obey His commands, is a liar, and the truth has no place in his heart.

He who says that he is in the light, and has hate in his heart for his brother, is still in the dark.

Do not love the world, nor the things in the world. If any one loves the world, there is no love in his heart for the Father.

Everyone who hates (works against) his brother [in Christ] is [at heart] a murderer [by God’s standards]; and you know that no murderer has eternal life abiding in him.

But whoever has the world’s goods, and sees his brother in need and closes his heart against him, how does the love of God abide in him?

We will know by this that we are of the truth, and will assure our heart before Him

For if our heart condemn us, God is greater than our heart, and knoweth all things.

Beloved, if our heart condemn us not, then have we confidence toward God.

He who believes in the Son of God has the testimony in his own heart: he who does not believe God has made Him a liar, in that he has refused to accept the testimony which God has given about His Son.

Little children (believers, dear ones), guard yourselves from idols—[false teachings, moral compromises, and anything that would take God’s place in your heart].