And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance. (Ac 2:1-4 KJ21)
Here is a teaching about the day of Pentecost from an independent source:
Thus Acts 2 must be interpreted as a special historical event, signifying a new period in God’s dealings with His people. Pentecost signals the dawning of the age of the Holy Spirit. And the fullness of the Spirit in God’s people is to empower them for witness to all the nations. The meaning of Pentecost is God’s equipping His church with the power of His Spirit so that He will be glorified among the nations. (Source: https://bible.org/seriespage/lesson-4-meaning-pentecost-acts-21-13)
Jesus kept His promise stated in Acts 1:5, “ . . . for John truly baptized with water, but you shall be baptized with the Holy Spirit not many days from now.”
THE HOLY SPIRIT IS A PERSON
The Holy Spirit is a person—not just a force.
And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption. (Eph 4:30) – Only a person can be grieved.
But Peter said, “Ananias, why has Satan filled your heart to lie to the Holy Spirit . . .” (Ac 5:3) and “You have not lied to men but to God.” (Act 5:4) – The Holy Spirit is the third person of the Holy Trinity. A human being can only lie to another person.
THE HOLY SPIRIT CAME TO INDWELL GOD’S PEOPLE
The Holy Spirit comes to live in us, and we become His temple.
. . . the Spirit of truth, whom the world cannot receive, because it neither sees Him nor knows Him; but you know Him, for He dwells with you and will be in you. (Joh 14:17)
Do you not know that you are the temple of God and that the Spirit of God dwells in you? (1 Cor 3:16)
Hold fast the pattern of sound words which you have heard from me, in faith and love which are in Christ Jesus. 14 That good thing which was committed to you, keep by the Holy Spirit who dwells in us. (2 Tim 1:13-14)
Or do you think that the Scripture says in vain, “The Spirit who dwells in us yearns jealously”? (Jas 4:5, emphasis added)
As you can see from these Scripture passages, the Lord Jesus sent the Holy Spirit to live within His people as our Teacher, Comforter, and Helper.
OUR GOD IS A GOD OF SIGNS, WONDERS & MIRACLES
Through faith in the gospel of Jesus Christ and the indwelling Spirit of God, the Lord has equipped His church to share the Good News, to operate in power and to speak the truth with holy boldness.
“Who is like You, O Lord, among the gods? Who is like You, glorious in holiness,
fearful in praises, doing wonders?” (Ex 15:11)
So the Lord brought us out of Egypt with a mighty hand and with an outstretched arm, with great terror and with signs and wonders. (Deu 26:8)
Therefore they stayed there a long time, speaking boldly in the Lord, who was bearing witness to the word of His grace, granting signs and wonders to be done by their hands. (Ac 14:3)
. . .in mighty signs and wonders, by the power of the Spirit of God, so that from Jerusalem and round about to Illyricum I have fully preached the gospel of Christ. (Rom 15:19, emphasis added)
God also bearing witness both with signs and wonders, with various miracles, and gifts of the Holy Spirit, according to His own will? (Heb 2:4)
As the Word tells us, we are equipped for every good work that will bring praise, honor, and glory to our God. (2 Tim 3:17) Glory to God! (For more about signs, wonders and miracles, see also Jeremiah 32:21; Daniel 4:2-3; 6:27; Mark 9:23; Matthew 19:26)