Why can only God forgive sins?

Sin, by its very nature, is an offense against God, and therefore only He has the authority to grant forgiveness. Acts 5:30-31 emphasizes that Christ was sent to provide forgiveness, a role that only the offended party can fulfill. Humans may seek to forgive one another, but the ultimate and eternal consequences of sin can only be addressed by the Lord Himself. The claims of men, who think they can earn forgiveness through works or free will, contradict the inherent nature of sin and the just requirements of divine grace.