'Heart' in the Bible

Therefore I was displeased with that generation, and said, 'They always err in their heart, but they didn't know my ways;'

Beware, brothers, lest perhaps there be in any one of you an evil heart of unbelief, in falling away from the living God;

For the word of God is living, and active, and sharper than any two-edged sword, and piercing even to the dividing of soul and spirit, of both joints and marrow, and is able to discern the thoughts and intentions of the heart.

"For this is the covenant that I will make with the house of Israel. After those days," says the Lord; "I will put my laws into their mind, I will also write them on their heart. I will be their God, and they will be my people.

"This is the covenant that I will make with them: 'After those days,' says the Lord, 'I will put my laws on their heart, I will also write them on their mind;'" then he says,

let's draw near with a true heart in fullness of faith, having our hearts sprinkled from an evil conscience, and having our body washed with pure water,

Don't be carried away by various and strange teachings, for it is good that the heart be established by grace, not by food, through which those who were so occupied were not benefited.