For Christians, Pentecost is a holiday on which we commemorate the coming of the Holy Spirit on the early followers of Jesus. Before the events of the first Pentecost, which came a few weeks after Jesus’ death and resurrection, there were followers of Jesus, but no movement that could be meaningfully called “the church.” Thus, from an historical point of view, Pentecost is the day on which the church was started. This is also true from a spiritual perspective, since the Spirit brings the church into existence and enlivens it. Thus Pentecost is the church’s birthday.