The apostle Paul teaches that tongues (languages) are only used to communicate intelligently, not gibberish. Tongues originally served as a sign for unbelievers.
In Pentecostalism, speaking in 'tongues' is the worshipped sign that God has accepted a person. Yet the miracle of Pentecost was not the speaking gibberish.
Adherents to the Pentecostal movement try to mimic some of the superficial surface manifestations of Acts 2 rather than follow the teaching given on that day.
Peter's first sermon took place on the Day of Pentecost, yet his subject seems to 'fit' the Day of Trumpets. Here is how Pentecost and Trumpets relate.
The receiving of God's Spirit is for God's creative effort in our lives. God's Spirit transforms us from a state of destruction into a state of purity.
Our historical and theological roots are advanced in a polished, chronological narrative (Acts), perhaps designed as a trial document authored by Luke.
Waiting for God is an acquired virtue requiring patience and longsuffering. Times of waiting are times to practice obedience and fellowship with others.
When we receive God's Spirit, we cannot escape the responsibility of using it, being a light to the world in the correct way of living. Hi Spirit is His power.
When Jesus told the religious leaders they would see Him seated at God's right hand and coming on the clouds, He did not mean they would be alive at His return.
Pentecost commemorates the establishment of the church and the bestowal of spiritual gifts through God's Spirit. We need to use these gifts responsibly.
Although Peter was given responsibilities of leadership, as connoted from the rock imagery or symbolism, he was not granted the post of 'vicar of Christ.'
I Corinthians gives ready instruction in the order and decorum that is fitting for church organization, as well as the Passover and weekly service.