“Jesus said to them again, ‘Peace be with you. As the Father has sent me, even so I send you.’ And when he had said this, he breathed on them, and said to them, ‘Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained.’ “
Since all believers have the same Holy Spirit, then all believers can have the same ability to retain or remit other’s sins.