Note 5 at Ac 2:4: It is not completely clear who was included in this "they." In Ac 1, Luke spoke of 120 men and women being present in the Upper Room, but it cannot be said for sure that all of those were present when the Holy Spirit came. It can be safely assumed that the eleven apostles who were waiting, as Jesus had commanded them (Ac 1:4-5), spoke in tongues. It is also very possible that others or all of the believers who were present in the Upper Room spoke in tongues.

Either way, in Peter's sermon to the people, he quoted Joe 2:28-29, and he interpreted this outpouring of the Holy Ghost "upon the servants and upon the handmaids" as being for all the people who were present (over 3,000, Ac 2:41) and for their "children, and to all that are afar off" (that's us, Ac 2:39). This forever proves that this gift of tongues was not just for a very few apostles.

Note 6 at Ac 2:4: This filling of the Holy Ghost was subsequent to the born-again experience (see note 27 at Joh 14:17). Paul later revealed in Ro 10:9 that people had to confess with their mouths that Jesus is Lord and believe in their hearts that Jesus was raised from the dead before they could be saved.

These disciples had already done this. Joh 20:28 specifically records Thomas kneeling before the resurrected Jesus and confessing that Jesus was both Lord and God. No doubt all of these disciples had already been saved, yet they had not received the baptism of the Holy Ghost. This same thing was true of the people who believed on Jesus in Ac 8:12-17 and 19:2-7.

Therefore, it is possible to be saved yet not have the baptism of the Holy Spirit that Jesus spoke of (Joh 7:37-39 and Ac 1:4-5). Since the Holy Spirit has been given and we do not have to tarry for His coming, we can receive salvation and the baptism of the Holy Spirit at the same time, but it is not automatic. We must ask and believe (Mt 7:7 and Lu 11:13) for the baptism of the Holy Ghost, just as we believed for salvation.

Note 7 at Ac 2:4: Speaking in tongues is unique to the church age. This is because when we believers speak in tongues, our new, born-again (see note 2 at Joh 3:3) spirits are speaking (1Co 14:14), not our minds. Before salvation, our spirits were the part of us that was "dead in trespasses and sins" (Eph 2:1). Therefore, until we received new spirits (2Co 5:17), the Holy Ghost could not give us this supernatural communication with the Father.

However, this experience was prophesied in the Old Testament. Joel prophesied about it in Joe 2:28-29. Peter referred to this passage in his explanation of this miracle. Isaiah spoke very specifically of speaking in tongues in Isa 28:11-12, and Jesus also said believers would speak with new tongues (Mr 16:17).

Note 8 at Ac 2:4: The other tongues that these disciples spoke in were languages other than their own; they hadn't learned them before. These tongues were different than the tongues that Paul was giving instructions about in 1Co 12-14, in that these were known languages.

Two kinds of speaking in tongues are very clearly spoken of in 1Co 13:1. They are called "the tongues of men and of angels." The tongues of men are the known languages, like the disciples spoke in here. The tongues of angels, or heavenly languages, are the tongues that all Spirit-filled believers can speak in. This is what Paul was speaking about in 1Co 12-14.

This is the only example of believers speaking in known languages that is recorded in the Bible. The other instances of speaking in tongues (Ac 8:18 [implied], 10:45-46, and 19:6) were evidently the heavenly languages unknown to men.

Note 9 at Ac 2:4: This speaking in tongues was not as many have envisioned it. The Holy Spirit did not take possession of the disciples to the point that they had no control over what was happening.

Paul made a special point of this in his letter to the Corinthians about how the gifts should be properly administered. He told the Corinthians to control themselves and not speak in tongues in church unless there was an accompanying interpretation (1Co 14:27-28). He would not have told them this if they had no control over the gift.

The gift of speaking in tongues is no different than the ministry gifts listed in Eph 4:11. True ministers of God also operate in a supernatural gift when they preach or teach. Peter was being used of the Holy Spirit just as much when he preached to this crowd as when he spoke to them in tongues. Yet no one expected him to simply open his mouth and have God supernaturally control it.

The Holy Spirit inspires and anoints preachers, but the ministers' wills are still intact; the degree to which the Holy Spirit uses the message is largely dependent on how much the individuals yield to His control. This is how it is with speaking in tongues. The Holy Spirit gives people the utterance, but they must exercise their faith to speak (Mr 16:17) and believe that the result is inspired by God (Lu 11:9-13).

Failure to understand this one truth has caused many people to ask the Lord for the gift of tongues and then wait for the Lord to supernaturally move their mouths. If nothing happens, they say that the Lord must not want them to speak in tongues or else it would have happened.

That is no more true than to say that every person the Lord has called to preach is preaching or every person He has given a prophecy to has prophesied. We have to step out in faith.