I asked Fr. Jairo why the Apostles didn’t leave Jerusalem after Jesus was killed. We read that they were afraid of the Jews, afraid that the same thing would happen to them. And yet they stuck together in the place (I suppose) where they had the Passover meal. Fr. Jairo’s explanation was complicated. He explained it in this way:
The Gospel of John was written in a time of persecution. It wasn’t a newspaper story as we might read. The Apostles were together to show us that the way to experience Christ is as a community. That is how the early Christians experienced the Lord with them; it is how we experience His Presence with us.