Who are those sent by Jesus to reconcile the world?

In this account of St. John there are two parts that are not present in the other accounts of the first encounter of the Risen Jesus with his disciples, namely, the breath, by which he gives them the Spirit, and the command to forgive sins. Why is he here in St. John and not in the other Gospels? The accounts of the encounters of the Risen Jesus with the disciples are present in all the Gospels. At least in St. Luke and St. John, there is a meet…