In the Old Testament, Pentecost was the offering of first fruits, a memorial of the establishment of the Mosaic Covenant. Along with Passover and Tabernacles, it was one of three times during which the Law required Jewish men to present themselves at the Sanctuary.
By New Testament times, hardly anyone was able to get to Jerusalem for all three festivals. The largest number of foreigners came for Pentecost (Greek, by the way, for “fiftieth,” because it started fifty days from Passover).
The year of our Lord’s death and resurrection, Pentecost began ten days after the Ascension. The disciples had been waiting in Jerusalem for the promised empowerment of the Holy Spirit.
Just as Pentecost as a Jewish festival marked the beginning of a special covenant, so the the Christian Pentecost. Just as the Jewish Pentecost represented the offering of first fruits, the 120 Christians gathered in one place represented the first fruits of coming harvest under that new covenant.
Miracle fire attended God’s first appearance to Moses and accompanied the Hebrew people out of Egypt and through the wilderness. It did not burn or harm.
Ruach, Hebrew for “spirit,” also means wind.
Luke records three distinct miracles on the day of Pentecost. In the first, a wind people could hear but apparently not feel filled the room where the believers sat. The second involved a fire that did not burn or harm anyone.
Both of these have Old-Testament antecedents. God did a new thing with the third miracle. All 120 believers began to speak in tongues. Luke records more than a dozen groups of visitors who heard the believers praising God in their own language.
For some reason, the modern church has divided over tongues. Some Christians find it downright embarrassing. They try to explain it away, claiming that it was more a miracle of hearing than speaking.
The more extreme representatives of this view actively try to discourage any discussion of tongues, refuse to extend fellowship to those who speak in tongues, and perhaps even claim that spiritual gifts passed away with the early church, and that modern interest in tongues comes from the devil!
Other Christians embrace tongues as a prayer language, at least, and perhaps even welcome public messages in tongues in their church services. The more extreme among them claim that people who do not speak in tongues have only a second-class experience in the Holy Spirit, or perhaps are not saved at all.
At Babel, man tried to ascend to the heavens to take God’s place. God divided them by making their speech mutually unintelligible. At Pentecost, God’s Holy Spirit descended to earth to stay. He invites people to come to Jesus and eventually to heaven. All may come by invitation where none may come to conquer.
If Pentecost reverses Babel, why not have a language by which all may speak to God even though, usually, no other person can understand?
The only thing devilish about the whole subject is the church dividing over something that God sent to unify the world. If we can’t totally agree, then we at least ought to respect and love each other.