Peter preaching – Acts 2
On the day of Pentecost, when so many people were focused on Jerusalem as the centre of Jewish worship, God demonstrated that He had a wider agenda. The disciples of the Lord were enabled by the Holy Spirit, to speak of the wonderful works of God in many different languages. God was reaching out beyond Jerusalem, beyond the Jews, to save people of every nation.
So Peter explained the life of Jesus:
In the last days God said :'I will pour out my Spirit upon all people ........'
Peter continues: " People of Israel listen. God publicly endorsed Jesus of Nazareth by doing wonderful miracles, wonders and signs through Him, as you know. But Jesus was delivered up according to the definite plan and foreknowledge of God. With the help of lawless Gentiles you nailed Him to the cross and murdered Him. However God released Him from the horrors of death and raised Him to life again, for death could not keep Him in its grip."
Peter concludes his message:
"Know for certain that God has made this Jesus whom you crucified, to be both Lord and Messiah (Christ the anointed one)."
My summary of this is - God at work
The end of the message brought promises of forgiveness, salvation, the Holy Spirit.
Read this account in Acts 2 again and remember Peter is speaking , not from himself, but by the Holy Spirit – speaking for God.
And many did respond in repentance and faith, showing their change of mind by baptism and joining with the disciples in commitment to the risen Lord and one another.