How do we know that humans are totally depraved?

Total depravity, a core belief in Reformed theology, is articulated through scripture, notably Romans 3:10-12, which states that 'there is none righteous, no, not one.' This doctrine asserts that every aspect of humanity—mind, will, heart, and flesh—is affected by sin. Therefore, no one can achieve goodness or righteousness on their own merit. The fall of Adam resulted in a sinful nature being passed down to all humanity, rendering them incapable of choosing God without the regenerative work of the Holy Spirit. This truth illuminates the need for divine intervention for any hope of salvation, further highlighting God's grace as the sole means by which a person can be made right before Him.