When understanding the beginnings of the Church at Pentecost, we must first understand that there were two distinct groups there that day.  The group that first received the Holy Spirit in Acts 2:2-13 were the 120 “brothers” or disciples mentioned in Acts 1:15.  They became the first ones to receive the Holy Spirit and became the first members of the Church or Body of Christ. 

Peter and the 11 stand up in verse 14 and begin preaching to the unsaved “Jewish men.”  By Acts 2:41, Scripture records that out of this Jewish crowd, 3,000 were saved.  Logically, this 3,000 were “added” to the 120 Church members that already existed from the Spiritual outpouring that occurred in Acts 2:2-4.

The Bible assuredly reveals that the Church was born on the Day of Pentecost if you correctly believe in Spiritual Baptism.  1 Corinthians 12:13 states that “for by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.”  The “one body” is clearly the CHURCH. 

Once you have the Holy Spirit you cannot lose it or obtain again.  The original 11 apostles could not have ever received the Holy Spirit prior to the Day of Pentecost because Acts 2:4 states that “they were ALL filled;” this included the original 11.  Jesus did not baptize with the Spirit prior to Matthew chapter 16 because in verse 18, He proclaims that “He WILL build [the] Church.”  The future tense of the verb clearly shows that the Church had not yet been built, and Christ never lies. 

Also, you can only become a member of the Church or Body of Christ by believing in the death, burial, and resurrection of Jesus Christ.  No one could have even become a saved member of the Church prior to Resurrection Sunday.  In John 20:22, Jesus breathes on the apostles and tells them to “Receive the Holy Spirit.”  However, the Word does not record that anyone was filled with the Holy Spirit on that occasion. 

On the day He ascended into Heaven (40 days after the Resurrection – Acts 1:3), as recorded in Acts chapter 1:5, the Lord stated, “for John baptized with water, but you WILL BE  baptized with the Holy Spirit,  NOT MANY DAYS FROM NOW.”  Based on all of these Scriptural facts, the birthday of the Church is undoubtedly the Day of Pentecost.