The Bible has much to say about the heart of man.
The word “heart” in the New King James Version of the Bible is found 835 times in 775 verses. (Ref “E-Sword”.)
God knows all of our hearts,
I Kings 8:39 (NKJV)
“For you alone know the hearts of all the sons of men.”
The question is, do you and I know our own heart?