How large was the crowd Peter preached to in Acts 2?
Peter preached to a great crowd of Jews at Pentecost, likely numbering thousands rather than merely 40 or 50. They had gathered in the whole temple complex from every nation under heaven. After hearing that they had crucified their promised Messiah, they were pricked in their heart and asked what they should do.
Les explains that Peter was not speaking to only 40 or 50 people. Because it was the Feast of Pentecost and Jews had come from every nation under heaven, there were probably thousands out there in front of him in the whole temple complex. Peter was addressing this great crowd of Jews on covenant ground. He accused them of having killed and murdered their Messiah, and when they heard this, they were pricked in their heart and asked Peter and the rest of the apostles, “What shall we do?”