The Heart is Deceptive
"The heart is deceitful above all things, and desperately sick; who can understand it? "I the Lord search the heart and test the mind, to give every man according to his ways, according to the fruit of his deeds."" (Jeremiah 17:9-10)
“God, who knows the heart, showed that He accepted them by giving the Holy Spirit to them, just as He did to us” (Acts 15:8).
“For the LORD searches every heart and understands every motive behind the thoughts” (1 Chronicles 28:9).
“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” (Hebrews 4:12).