Kinds of hearts in the Bible

God searches and knows all hearts

1 Samuel 16:7 

But the LORD said to Samuel, “Do not consider his appearance or his height, for I have rejected him. The LORD does not look at the things man looks at. Man looks at the outward appearance, but the LORD looks at the heart.”

1 Chronicles 28:9 

“And you, my son Solomon, acknowledge the God of your father, and serve him with wholehearted devotion and with a willing mind, for the LORD searches every heart and understands every motive behind the thoughts. If you seek him, he will be found by you; but if you forsake him, he will reject you forever.

Jeremiah 17:9-10 

9 The heart is deceitful above all things and beyond cure. Who can understand it?

10 “I the LORD search the heart and examine the mind, to reward a man according to his conduct, according to what his deeds deserve.”

Ezekiel 11:5 

Then the Spirit of the LORD came upon me, and he told me to say: “This is what the LORD says: That is what you are saying, O house of Israel, but I know what is going through your mind.

Luke 16:15 

He said to them, “You are the ones who justify yourselves in the eyes of men, but God knows your hearts. What is highly valued among men is detestable in God's sight.

Romans 8:27 

And he who searches our hearts knows the mind of the Spirit, because the Spirit intercedes for the saints in accordance with God's will.

Hebrews 4:12 

For the word of God is living and active. Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart.

Hard

Deuteronomy 15:7

  If there is a poor man among your brothers in any of the towns of the land that the LORD your God is giving you, do not be hardhearted or tightfisted toward your poor brother.

Psalms 95:8

 Do not harden your hearts as you did at Meribah, as you did that day at Massah in the desert,

Hebrews 3:8

 Do not harden your hearts as you did in the rebellion, during the time of testing in the desert,

Mischievous

Proverbs 28:14

 Blessed is the man who always fears the LORD, but he who hardens his heart falls into trouble.

Proverbs 22:15

 Folly is bound up in the heart of a child, but the rod of discipline will drive it far from him.

Romans 12:1 

Therefore, I urge you, brothers, in view of God's mercy, to offer your bodies as living sacrifices, holy and pleasing to God—this is your spiritual act of worship.