Peter explains the event of Pentecost and explains the gospel, proving his point from the book of Joel and the Psalms. The listeners are convicted of their sin and ask, "What shall we do?" Many received the Lord.
The Book of Acts. The work that the Lord Jesus began to do and teach is continued in the book of Acts with the descent of the Holy Spirit, by the Holy Spirit through the witness of the apostles. The book is history, example, doctrine, and a primer for Christian living.