The Holy Spirit had come upon all the apostles, and they were speaking about God's wonderful power in many different and identifiable languages (Acts 2:4; Acts 2:7-11).  Their excitement and the gathering crowd attracted still more people to ask what was going on (Acts 2:12).  Peter was the spokesman: he simply quoted from the Old Testament writings of Joel (Joel 2:28-32).  The coming of the Holy Spirit to every believer had been predicted almost 800 years previously.

Joel had seen through the material prosperity of his time, to the dreadful spiritual poverty of Israel.  Religious rites were useless unless the worshippers were right before the Lord; and so he urged the nation to repent, because God was coming to judge His people (Joel 2:12-14).  The same situation existed at Pentecost: a glut of religion and a dearth of real relationship with God.  They hated Jesus, the Saviour, and after killing Him they had no protection against God's wrath (John 3:36).

The Spirit came to all believers: young and old, male and female.  The evidence was that those who were gifted as apostles, prophets, evangelists, pastors and teachers spoke God's Word, just as God had done through the Old Testament prophets (2 Peter 1:20-21).  Peter knew that the message was still the same, but the Holy Spirit had brought everything about Jesus into sharp focus.  Jesus will come back to judge; that is why every truth spoken and every sign observed is a challenge to repent.  Some of the global and cosmic signs have not yet been fulfilled, but Jesus promised that they will be before He returns (Matthew 24:29-30).  That delay does not detract from the message; in fact every extra day before Christ's return makes us more accountable because the world has had more time to repent (2 Peter 3:9).

Peter said that God was still speaking in the present through Joel ('In the last days, God says …').  Once He has spoken, His Word remains true until its final fulfilment.  He continues to speak today through the Bible because He inspired the original writers (1 Peter 1:10-12).  The message remains the same today: repent and trust Jesus as Saviour now.  He does not bring blessings to religious people who continue in sin.  He brings salvation for all who turn to Him and away from their sin.  Conversion without repentance is useless fake religious insurance.  If you are not trusting Jesus today, repent quickly before He returns (www.crosscheck.org.uk).  If you know you are saved, let God fill you with His Spirit daily, enabling you to be His gospel messenger to your friends and colleagues (Acts 1:8).