What does the Bible say about the nature of fallen man's heart?

The Scripture states that the heart of man is deceitful above all things and desperately wicked (Jeremiah 17:9). This fallen condition is illustrated vividly at the crucifixion of Christ, where those present displayed enmity and hatred toward the Lord, culminating in His rejection and crucifixion. The natural man's hostility toward God is ultimately demonstrated by his unwillingness to submit to God's sovereign rule, which reflects the inherent depravity that exists within every individual by nature.