So you admit that the Day of Pentecost was not about salvation? They were already saved before that Day?
Luke gives the setting in Acts one:
Acts 1:2 until the day in which he was received up, after that he had given commandment through the Holy Spirit unto
the apostles whom he had chosen:
--The apostles; the chosen ones. They were saved. They were the very ones that he had chosen and taught.
Acts 1:4 and, being assembled together with them, he charged them not to depart from Jerusalem, but to wait for the promise of the Father, which,
said he, ye heard from me:
--They were saved, and yet were commanded not to depart from Jerusalem but wait for the promise of the Father, which is the Holy Spirit. They had not received Him yet.
Acts 1:5 For John indeed baptized with water; but ye shall be baptized in the Holy Spirit not many days hence.
--They had not received this baptism of the Holy Spirit yet. They were to wait for it. It would only happen once in their lifetime.
Acts 1:8 But ye shall receive power, when the Holy Spirit is come upon you: and ye shall be my witnesses both in Jerusalem, and in all Judaea and Samaria, and unto the uttermost part of the earth.
--When it would come it would come with power. The power would be directly related to witnessing.
Acts 1:12 Then returned they unto Jerusalem from the mount called Olivet, which is nigh unto Jerusalem, a Sabbath day's journey off.
--Then they obeyed the Lord, went from the Mount of Olives where they were, and returned to Jerusalem. While they were there they conducted some important business, as the selection of Matthias as the 12th apostle in the place of Judas.
Then the Day of Pentecost came:
Acts 2:1 And when the day of Pentecost was now come, they were all together in one place.
--Various signs took place: cloven tongues of fire, a mighty rushing wind, and speaking in tongues or languages.
Acts 2:2 And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.
3 And there appeared unto them cloven tongues like as of fire, and it sat upon each of them.
Acts 2:4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
--This is what Jesus had been speaking about. They were filled with the Holy Spirit. They spoke with other languages. This was the miracle that they were able to speak in other known languages miraculously. The Holy Spirit gave them that ability to speak (utter) in other languages. These were languages that they could now understand, but formerly could not.
It was not chaos that gathered attention; it was other people speaking in known languages.
Acts 2:7 And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galilaeans?
8 And how hear we every man in our own tongue, wherein we were born?
Verse 8 is important. Every man heard their own language. Various individuals were speaking in languages that were represented there. There is a list of them given--about 13 in all. Out of 120 disciples God had given them the ability to speak in these 13 language groups, and each one could pick out or hear their own language, or which one was speaking their own native tongue. But these people were simple Galileans.
This was a sign to the Jews. Tongues is always a sign to the Jews.
It was also a sign for the apostles, that what they said was from God. The Jews had to know that the very disciples that spoke these tongues (and the ones with them), were speaking God's message. It was ordained from God.
It got their attention.
From this point onward every believer that would come to Christ would be indwelt with the Holy Spirit. This is the significance of the Day of Pentecost. There would never be any "subsequent blessing" or baptism. It would happen here or at the day of salvation.
This attention to tongues then gave Peter the opportunity to preach:
Acts 2:14 But Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judaea, and all
ye that dwell at Jerusalem, be this known unto you, and hearken to my words:
Acts 2:16 But this is that which was spoken by the prophet Joel;
Acts 2:36 Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ.
It was a convicting sermon that spoke right to their hearts.
Out of approximately 100,000 that were present only 3,000 got saved. The rest of the Jews rejected Christ as their Messiah and continued to reject tongues as a sign. Eventually judgment came upon them in 70 A.D., and the sign of tongues ceased shortly after that.