Exodus 32: 26 – 28: Then Moses stood in the gate of the camp, and said, Who is on the LORD’S side? let him come unto me. And all the sons of Levi gathered themselves together unto him. And he said unto them, Thus saith the LORD God of Israel, Put every man his sword by his side, and go in and out from gate to gate throughout the camp, and slay every man his brother, and every man his companion, and every man his neighbour. And the children of Levi did according to the word of Moses: and there fell of the people that day about three thousand men.
Acts 2: 40 – 41: And with many other words did he testify and exhort, saying, Save yourselves from this untoward generation. Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls.
Moses received the Law on Mount Sinai fifty days after the Passover in Egypt. The Feast of Shavuot (or Pentecost) was later instituted to commemorate the giving of the Law to Moses (Leviticus 23: 15 – 22). About a thousand years after the giving of the Law, the Spirit of God fell to empower the new covenant, and entered 120 disciples gathered in an upper room in Jerusalem. This momentous event that birthed the early Church happened on the Feast of Shavuot (Acts 2: 1 – 4), fifty days after Jesus’ resurrection, for Christ was our Passover who was sacrificed for us (1 Corinthians 5: 7).
From this we learn that the Spirit of God was given to the Church on the same day that the Law of God was given to Israel. The two covenants (the Old Testament and the New Testament) were inaugurated and joined together on the same day. When the Law was given on the first Pentecost, judgment happened and about three thousand people were killed because of Israel’s idolatry and worship of the golden calf. When the Spirit was given to the Church at the second Pentecost, salvation happened and about three thousand people received eternal life. The Law can tell us the will of God, but only the Spirit can give us the power to live it (2 Corinthians 3: 6 says: Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.).