The Pentecost crowd had first gathered because of an unusual sound (Acts 2:6). Then the cosmopolitan pilgrims in Jerusalem heard the apostles telling them about God's wonderful power; but each nationality heard in their own language (Acts 2:8). Peter explained that it was what Joel had prophesied (Acts 2:9-21), and went on to talk about Jesus. Quoting the Old Testament Scriptures, Peter convinced them that Jesus was the Messiah and God's appointed ruler over everything (Acts 2:22-35).

It was a moment of realisation for the crowd: they had killed the Messiah, but God had raised Him to life again. As they had proved to be His enemies, they were liable to be judged by Him. They got the message. The Holy Spirit convicted them that they were in the wrong and they were distraught. They did not know what to do and so they asked the apostles. The answer was simple: repent. They had to admit they were wrong and be willing to show it.

Baptism was a sign of a spiritual new start. Non-Jews who wanted to become Jews were baptised. John baptised Jews who knew they were not ready to meet God, but refused baptism to people who did not repent (Matthew 3:5-8). Jesus commanded that new disciples should be baptised (Matthew 28:19), which is why Peter commanded that their repentance should be accompanied by a willingness to submit to baptism. The promise of forgiveness and the gift of the Holy Spirit was not just for the individuals who repented that day. God would honour His promise everywhere people responded to the gospel, and in every future generation.

God still calls people to repent of their rebellion towards Him, and honour Jesus their Saviour, by confessing their sins and being baptised. The Holy Spirit is given to all who come to Christ to be made children of God (John 1:12). The church, you and I, are responsible for telling people the facts about Jesus, and of their accountability before Him. And so God works through His people to call others. The Holy Spirit helps them (Acts 1:8): indeed, without His power there is no effective gospel ministry. That is why God will give you the right words so that you can work with Him, as He calls people into His kingdom. So do not be afraid anymore; speak the truth in love and allow the Holy Spirit to use you, so that you share in His business of salvation wherever you live and work.