How do we know the doctrine of the heart's corruption is true?

Scripture repeatedly emphasizes the total depravity of humanity due to sin. Romans 3:23 asserts that all have sinned and fall short of the glory of God, and Jeremiah 17:9 notes that the heart is deceitful above all things and desperately wicked. This doctrine aligns with the understanding that our speech and actions are reflective of our inner condition; a heart that is corrupt will inevitably produce sinful words and behaviors. The realization of this corruption points us toward our need for redemption in Christ, who alone can cleanse our hearts from such sin.