Some cynic has said that if it were up to most of its members modern churches would have on their steeples lightning rods instead of crosses in memory of that time when lightning struck the early church and as protection against it ever happening again.
On the Day of Pentecost lightning struck the early church. They were gathered in an upper room in Jerusalem. All the original twelve were there, save one. Judas' place had been taken by Matthias, who had been chosen by the casting of lots. That this was an unreliable means of choosing officers for the board is attested to by the fact that Matthias is never mentioned again.
Jesus' brothers were there. The resurrection had obviously healed some wounds because his brothers had been embarrassed earlier by Jesus' ministry. His mother was there…