Sin cannot be tied up and thrown into a fire. It cannot be put in a box or glued to a stick. It is rebellion. It is rebellion in the heart. It is breaking God's Law.
Sin occurs inside the heart and mind of people.
Therefore, God must punish the sinner. Because He is both Holy and Just and the person who sins offends God. God's Holy and Just character will not allow Him to ignore this offense. When He commanded that the oceans be, they came into existence. God's word is powerful.