What does the Bible say about the nature of human hearts?

Jeremiah 17:9 presents a sobering reality about the human heart, declaring it to be deceitful above all things and desperately sick. This reflects the depravity inherent in humanity due to sin. The sinful nature of humans calls for a divine intervention for true change. Only through Jesus Christ can one receive a new heart, as emphasized in the New Covenant promised in Ezekiel 36:26, where God promises to give His people a new heart and put a new spirit within them. This transformation is necessary for salvation and a genuine relationship with God. Christians are called to recognize this truth about their hearts in order to rely on Christ for spiritual renewal and growth, understanding that apart from Him, they can do nothing that is truly good or pleasing in the sight of God.