"The Church is incapable of forgiving any sin without Christ, and Christ is unwilling to forgive any sin without the Church. The Church cannot forgive the sin of one who has not repented, who has not been touched by Christ; Christ will not forgive the sin of one who despises the Church." (Blessed Isaac of Stella) Mystery but God's plan. Just as a person is saved, whether they know the Church or not, through the Church by God's grace, so all sin is forgiven through the Church, whether the person is aware of the Church or not. That is why Christ established his Church on earth.