Consider who Peter was speaking to - Men of Judea and all who live in Jerusalem (2:14)and You that are Israelites (2:22). The ones "living in Jerusalem" would have been Israelites, just not permanently living there. Deuteronomy 16:2, 5-6 says
You shall offer the passover sacrifice to the Lord your God, from the flock and the herd, at the place that the Lord will choose as a dwelling for his name. You are not permitted to offer the passover sacrifice within any of your towns that the Lord your God is giving you. But at the place that the Lord your God will choose as a dwelling for his name, only there shall you offer the passover sacrifice, in the evening at sunset, the time of day when you departed from Egypt.
Mary and Joseph did this as well:
Luke 2:41
Now every year his parents went to Jerusalem for the festival of the Passover.
Then, regarding the feast of Weeks, or Pentecost, Deuteronomy 16:11 says
Rejoice before the Lord your God....at the place that the Lord your God will choose as a dwelling for his name.
Considering the long travel, many would stay the entire 7 weeks from Passover to Pentecost. This is why there were so many people there from other nations (Acts 2:8-11). These were not just Jews who wanted a vacation, these were devout Jews. What's so special about being called devout?
Eulabes - inner reverence. Used only 4 times in the NT, it seems to always signify someone who is in righteous standing with God. In other words, saved people.
In Luke 2:25-26, Simeon was described as "eulabes" and was waiting for the consolation of Israel. It was revealed to him by the Holy Spirit that he would not see death until he had seen the Lord's Messiah.
In Acts 8:2, "eulabes" men buried Stephen and made loud lamentation over him after he was stoned to death. Stephen's enemies sure would not have lamented. It would have been his brothers in Christ who were deeply saddened
In Acts 22:12, Paul recounts how Ananias, a "eulabes" man, laid his hands on him to receive his sight after Paul (Saul) had become a believer.
It is this same "eulabes" which is used to describe the men who were gathered from all the nations in Acts 2. Verse 5 says
Now there were eulabes Jews from every nation under heaven living in Jerusalem.
These men, who were waiting for the consolation of Israel, would have been justified by faith before Jesus was crucified. In other words, they were already "saved"
They had been there to see Jesus ride into Jerusalem on a donkey. Matthew 21:8-9 says that a very large crowd spread their coats and went ahead of Him singing "Hosanna"
If you read John 12, you see a great mix of people in this crowd. Some who believed in Him and some who did not. Verses 17 and 18 describe two groups of people - those who were with him when He raised Lazarus from the dead had gone about testifying. A different crowd heard about it and went to see Jesus. The English isn't real clear that there were two different crowds, but that is the case.
Matthew 27:20 also testifies that there were multiple "crowds" that were stirred into asking for Barabbas to be released. These "devout" men from Acts 2 were part of the crowds that cried out "Crucify Him"
That is why Peter said to them in Acts 2:26
Therefore let the entire house of Israel know with certainty that God has made him both Lord and Messiah, this Jesus whom you crucified.
These men were most certainly pricked in their hearts, having taken part in the murder of their long-awaited Messiah. They knew better, but had allowed themselves to be deceived, and they went along with the crowd.
When Peter told them to be baptized for the remission of sins, this was not justification. It was a cleansing of the conscience (2Peter 3:21) and a restoration into fellowship with God. It was also a public association with Jesus and His followers, which would have brought persecution.
See in John 12:42 how some Pharisees believed in Jesus, but would not confess Him, for fear of being put out of the synagogue.
Only when they had received forgiveness for this atrocity would these devout men receive the gift of the Holy Spirit.
It is always spoken of this event that "3,000 me were saved at Pentecost"
But nowhere does it say that these men were saved. Why is that? They already were saved before they came that day. Justified by faith in God, just like Abraham was (Romans 4:21-25)
What is actually said of these men, in Acts 2:41, is that
those who welcomed his message were baptized, and that day about three thousand persons were added.
Added to what? Added to the group of believing Jews who had recognized Jesus as their Messiah
Acts chapter 2 gives no evidence whatsoever that anyone was "saved" because they got baptized. It confirms that 3,000 pre-cross believers came to realize that they were accessories to the murder of the Messiah. But by being baptized as a public confession of their faith in Him, they were restored to fellowship with God and received the promised Holy Spirit
