How do we know that faith brings healing according to the Bible?

The text reveals that while all ten lepers were cleansed of their leprosy, it was the one who returned to Jesus that was truly healed. This demonstrates that faith is essential for complete restoration. Jesus confirmed this effect by saying, 'Thy faith hath made thee whole' (Luke 17:19), indicating that true faith leads to inner healing and wholeness beyond mere physical symptoms. In a Reformed understanding, this signifies that salvation is not only about the removal of sin's consequences but involves the transformative power of grace in the believer's heart.