Why is Pentecost called the birthday of the Church?

Answer 1

That is the Jewish feast day fifty days following Passover when the Holy Spirit is said to have come upon the apostles and other early believers in Jerusalem. The christians then via the Holy Spirit told the Gospel story to thousands of visiting Jews from other countries, each in their native language (even though the christians did not know those languages). Some of these Jews converted and when they returned home spread Christianity. It basically triggered the first "explosion" of Christianity into the world outside Jerusalem and Galilee. The fact that uneducated Galileans spoke so many different languages that day shocked many Jews.

Unlike the way Pentecostal churches interpret this scripture, I personally see no reason for another miracle such as this one these days. We have no shortage of educated trained translators to translate The Bible to any language needed now. The early christians did not and needed some help spreading the word. While God can do any miracle he wishes, he is not one to expend his efforts where they aren't needed or where he is not likely to receive the credit (especially if it would just build pride in the person getting the miracle, as is so common among Pentecostals).

BTW, I grew up in the AOG and am very familiar with Pentecostalism. Yet I can never be a Pentecostal because of what I believe is their misinterpretation of that section of Acts. I have spoken in "tongues", but it felt wrong; I am sure it was just babbling to satisfy peer pressure at that moment.

Answer 2

Pentecost is seen as the birthday of the Church because it marks the occasion when the Holy Spirit descended upon the apostles, empowering them to spread the teachings of Jesus and establish the Christian community. This event is considered the beginning of the church's mission to share the message of Christ with the world.