What happened on the Day of Pentecost almost 2000 years ago?

Pentecost is the day, almost 2000 years ago, that God began pouring out His Spirit.

God loves us so much that He took on the form of man to pay the price of death for our sins. Because of our love for Him, we repented and were baptized in His name Jesus, washing our sins away by the blood He shed for us. It is because God paid the price for our sins that He was able to begin pouring out His Spirit upon us.

"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." - Acts 2:1-4

This was prophesied by the prophet Joel in Joel 2:28.

"But this is that which was spoken by the prophet Joel; And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams: And on my servants and on my handmaidens I will pour out in those days of my Spirit; and they shall prophesy:" - Acts 2:16-18

On this day of Pentecost, Peter stood up with the eleven apostles, speaking with divine inspiration, full of the Holy Ghost. He preached the gospel – the death, burial, and resurrection of Jesus Christ.

"Ye men of Israel, hear these words; Jesus of Nazareth, a man approved of God among you by miracles and wonders and signs, which God did by him in the midst of you, as ye yourselves also know: Him, being delivered by the determinate counsel and foreknowledge of God, ye have taken, and by wicked hands have crucified and slain: Whom God hath raised up, having loosed the pains of death: because it was not possible that he should be holden of it." - Acts 2:22-24

"Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ." - Acts 2:36

The Jews that were gathered in Jerusalem for Pentecost from around the world were convicted in their hearts when they heard Peter preach the gospel of Jesus.

"Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?" - Acts 2:37

"Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call." - Acts 2:38-39

"And with many other words did he testify and exhort, saying, Save yourselves from this untoward generation." - Acts 2:40

"Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls. And they continued stedfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers. And fear came upon every soul: and many wonders and signs were done by the apostles." - Acts 2:41-43

"…And the Lord added to the church daily such as should be saved." - Acts 2:47