'Heart' in the Bible

[for] forty years. Therefore I was angry with this generation, and I said, 'They always go astray in their heart, and they do not know my ways.'

Watch out, brothers, lest there be in some of you an evil, unbelieving heart, [with the result that you] fall away from the living God.

For the word of God [is] living and active and sharper than any double-edged sword, and piercing as far as the division of soul and spirit, both joints and marrow, and able to judge the reflections and thoughts of the heart.

let us approach with a true heart in the full assurance of faith, our hearts sprinkled [clean] from an evil conscience and our bodies washed with pure water.

Do not be carried away by various and strange teachings, for [it is] good [for] the heart to be strengthened by grace, not by foods by which those who participate have not benefited.