The phrase "secret of the heart" (or very similar) only occurs in a number of places in the Bible as follows:
- 1 Chron 28:9 - As for you, Solomon my son, know the God of your father and serve Him wholeheartedly and with a willing mind, for the LORD searches every heart and understands the intent of every thought. If you seek Him, He will be found by you; but if you forsake Him, He will reject you forever.
- Ps 44:21 - would not God have discovered, since He knows the secrets of the heart?
- Prov 15:11 - Sheol and Abaddon lie open before the LORD—how much more the hearts of men! [ie, the secrets of men's hearts]
- Jer 11:20 - O LORD of Heaven’s Armies, you make righteous judgments, and you examine the deepest thoughts and secrets. Let me see your vengeance against them, for I have committed my cause to you.
- Jer 17:10 - I, the LORD, search the heart; I examine the mind to reward a man according to his way, by what his deeds deserve. [Compare Rev 2:23, Rom 8:27]
- Jer 20:12 - O LORD of Hosts, who examines the righteous, who sees the heart and mind, let me see Your vengeance upon them, for to You I have committed my cause.
- Dan 2:30 - And it is not because I am wiser than anyone else that I know the secret of your dream, but because God wants you to understand what was in your heart.
- Luke 2:35 - so that the thoughts of many hearts will be revealed—and a sword will pierce your soul as well.”
- Rom 2:16 - on the day when God will judge men’s secrets through Christ Jesus, as proclaimed by my gospel.
- Rom 8:27 - And He who searches our hearts knows the mind of the Spirit, because the Spirit intercedes for the saints according to the will of God.
- 1 Cor 14:25 - and the secrets of his heart will be made known. So he will fall facedown and worship God, proclaiming, “God is truly among you!”
- Rev 2:23 - Then I will strike her children dead, and all the churches will know that I am the One who searches minds and hearts, and I will repay each of you according to your deeds.
Let us observe several things that emerge as a pattern throughout these survey:
- The one who is capable of "searching hearts and minds" in the OT was YHWH, Jehovah God almighty. In the NT this is Jesus.
- The ability to search hearts and minds is one of the distinguishing characteristics of the omniscience of the one true God. Indeed, this was the point of the story of Daniel 2 - the true God of Israel, YHWH, had vastly superior ability compared to the false gods of Babylon. Not only was God able to read men's minds, He was also able to know things that a man had forgotten!!
- The ability of God to know men's secrets, that this things not revealed to anyone else, will be revealed when Jesus returns in glory. It is this supernatural ability of God that makes His judgement of humans perfect - the motives reveal the true extent of our sinfulness.
- God, on some occasions, reveals the secrets of men's hears via His prophets to others. This includes inner thoughts and some times their secret sins. This was the point of the hideous story of David in 2 Sam 12, 13.
That is, the secrets of men's hearts, whether sinful knowledge or sinful acts in private, are all known to God who rewards and judges and reveals as His perfect knowledge dictates.
John 2:25 (NLT) No one needed to tell him about human nature, for he
knew what was in each person’s heart.