A new and courageous Peter stands up and preaches to a large crowd. Using Old Testament passages he quotes Joel and David to preach the gospel. In the last days, or Day of the Lord, he said, the Holy Spirit would be poured out on all mankind. This isn’t just a shower, but downpour of power to preach and to prophesy, which is speaking forth the heart of God as exhortation, encouragement and comfort toward men. Peter pointed out that Jesus was crucified both as part of the Father’s determined purpose and foreknowledge on one hand, and as man’s free will in their hatred for Him on the other. God’s purpose vs. man’s free will is a profound mystery to this day. The crowd knew all about Jesus and knew they were in need of Him and asked Peter what they should do.