'Heart' in the Bible

“He has blinded their eyes and He hardened their heart, so that they would not see with their eyes and perceive with their heart, and be converted and I heal them.”

During supper, the devil having already put into the heart of Judas Iscariot, the son of Simon, to betray Him,

“Do not let your heart be troubled; believe in God, believe also in Me.

Peace I leave with you; My peace I give to you; not as the world gives do I give to you. Do not let your heart be troubled, nor let it be fearful.

But because I have said these things to you, sorrow has filled your heart.

Therefore you too have grief now; but I will see you again, and your heart will rejoice, and no one will take your joy away from you.