Before Jesus died, His followers were called disciples, which means learners. After Jesus’ Resurrection, they were apostles which means, one who is sent out. No matter what name they were given, they were still His followers.
Simon Peter was then the preacher after the time of Pentecost. The one who died of old age peacefully was John. All the others died of being persecuted. Philip preached the gospel to the king Ethiopian and the Ethiopian preached the gospel to the city.
One day, Saul the chief persecutor was on the road to Jerusalem. God called down from Heaven. He was blind for three days and neither ate or drank when his eyes opened he became Paul and preached the gospel and he sometimes went to jail.
The purpose of the Council of Jerusalem was to help people come to Jesus and to help churches. The religion that had the most influence on Europe and Western Civilization was Christianity. Christianity was important, do you not think?