The Sun of righteousness is none other than the Lord Jesus Christ. His righteousness shines infinitely brighter than any other person who has ever lived. In the gospels you can read the story of his perfect life in the midst of all sorts of evil. His perfect devotedness to others even led him to the cross where he gave his life as a sacrifice for sinners.
The healing in his wings is what sinners need more desperately than anything else. His healing for our hearts begins the moment when we believe on the Lord Jesus Christ as our Savior and receive the forgiveness of sins. This healing continues throughout this life as we walk close to the Savior. When we reach heaven, our hearts are completely healed. We will never again experience a thought or wish unholy. How great will be our joy when our hearts are completely healed and we can enjoy the presence of the Lord Jesus. We can know this joy while on earth in some measure, but in heaven we will know it in a wonderful fullness. The Lord Jesus heals the heart, and it is a healing that no one should go without. Like rust to a car, moths to cloth, or rot to timber, sin has a way of destroying the heart. Because we are all sinners, we desperately need the healing Jesus Christ alone brings.
The fog of unbelief is so thick that men dont see how God is near to them. They
dont see that it is God who made them, who has provided and cared for them
every moment of their lives, and who now even at this very second is the one
who gives them the breath to keep them alive. He giveth to all, life, breath
and all things. (Acts 17:25)
Because of their unbelief they feel their lives are a closed system where God has nothing to do with them. However, nothing could be further from the truth. God dearly loves every human being. He desires that each one will share in his goodness for time and eternity. He has made a way for all persons to be saved from the guilt and power of sin. In grace he sent his Son into the world to die and wash away our sins. The blood of Jesus Christ his Son cleanseth us from all sin. (1 John 1:7). The blood shed on the cross washes our sins away when we believe so that we can be accounted righteous and stand justified before him.