It isn't fair... It is Grace and Mercy.

"Surely he took up our infirmities and carried our sorrows, yet we considered him stricken by God smitten by him, and afflicted. But He was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was upon him, and by his wounds we are healed. We all, like sheep have gone astray, each of us has turned to his own way; and the Lord has laid on him the iniquity of us all." Isaiah 53:4-6 (NIV, emphasis added)