How do we know Jesus' substitutionary work is true?

The account of Jesus touching the leper in Mark 1:41 illustrates the core of His substitutionary work. In touching the leper, Jesus willingly entered into the state of ceremonial defilement, an act that foreshadows His ultimate sacrifice. Though Jesus knew no sin, He was made sin for us, allowing us to be declared righteous before God. The leper's healing is an emblem of the greater spiritual healing available through Christ. By recognizing the gravity of sin and its consequences, we can appreciate the depth of Jesus' love and the lengths He goes for our redemption. This foundational truth assures us that through faith, all who come to Him are cleansed, not based on their merit but on His grace.