The Holy Spirit bestowed a gift upon the believers, and that gift was the ability to speak in tongues:
"Now there are diversities of gifts, but the same Spirit...For to one is given by the Spirit the word of wisdom; to another the word of knowledge by the same Spirit; To another faith by the same Spirit; to another the gifts of healing by the same Spirit; To another the working of miracles; to another prophecy; to another discerning of spirits; to another divers kinds of tongues; to another the interpretation of tongues" (1 Cor.12:4,8-10).
This was the promise of power spoken of here:
"But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth" (Acts 1:8).
There was no change except for the fact that this promise was fulfilled.
How significant was this fulfilled promise?
Acts 1:4-8
And, being assembled together with them, commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, saith he, ye have heard of me.
5 For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence.
6 When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel?
7 And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power.
8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.
1. They were commanded not to depart from Jerusalem
2. They were to wait for the promise of the Father, which, they heard from Jesus Christ. How significant is that?
3. As significant as the water baptism of John was to God towards Israel, it was to be replaced, as foretold in the Gospels, by baptism in Holy Spirit. Both Jesus and John the B, spoke of this eventuality in the gospels. Matthew 3:11-12, Luke 3:16-17, Mark 1:7-8, John 1:29-34. This promise is recorded in all four gospels. John made it clear that his water baptism was but temporary and would be replaced by Jesus Christ with a far greater baptism. How important was John's baptism in his time? How important is it to some present day denominations? Seeing, then that both John and Jesus foretold it, how important is the baptism in pneuma hagion?
4. Those present with him, asked in Acts 1:6 about the restoration of the nation of Israel. How important is the restoration of the nation of Israel? Yet Jesus Christ in answering that made it clear that compared to restoration, the far more important issue was the power they were to receive, the gift of pneuma hagion. How more important to Jesus Christ was it that they receive power? " But ye shall receive power...."
5. It is far more important that the twelve receive power than the restoration of Israel.
How important then, is the gift of Holy Spirit that they received on the day of Pentecost? Acts 2:1-4, 38, 10:44-47;11:15-18
The leadership in Jerusalem called Peter on the carpet, so to speak, Acts 11:4,when they heard that Peter had entered into the house of a Gentile. To the Judeans, Gentiles were but dogs, a most vile animal in that culture.
Yet it was the fact that the Gentiles of the house of Cornelius spoke in tongues that convinced the leadership in Jerusalem that God granted to the Gentiles repentance unto life.
Repentance unto what? Speaking in tongues? The promise of the Father as was spoken of by Jesus Christ?
Repentance unto life. Romans 6:23
The day of Pentecost was the birthday of the church of grace, grace that would reach out to the Gentiles and the entire world to all those that would choose to believe
The reception of the gift of the Holy Spirit was the proof that "God also to the Gentiles granted repentance to life" Acts 11:18