This weekend's First Reading features portions of Peter's Pentecost sermon. The chief of the apostles has just been filled with the Holy Spirit, and now he is preaching before a crowd of Jews from all over the known world. He is no longer the frightened, hesitant fisherman who was so quick to deny Jesus. He now has the power of the Spirit working within him, providing him with compelling words. He is no longer afraid to tell it like it is
And that's exactly what Peter does. He states the plain facts, and he begins by proclaiming exactly Who Jesus is. “Let the whole house of Israel know for certain,” he announces, “that God has made both Lord and Christ, this Jesus Whom you crucified.” Jesus is the Lord. He is divine. He is God Himself, the God-Man. Further, Jesus is the Messiah, the anointed One, the Christ, Whom the Jews had been expecting for centuries. Peter is very clear. There is no doubt about it. What's more, the Jews crucified this Jesus. Peter puts the blame squarely on his audience: “this Jesus Whom you crucified” (emphasis mine).
Peter is so forceful that his listeners are “cut to the heart.” The Greek verb here is katanussō, and it means to be pricked; to be emotionally agitated, especially by sorrow; to be pierced all the way down to the core; and to be pained in the mind. Peter's simple, straightforward speech has affected his listeners to the depths of their being. They feel their guilt, they are sorry, and they ask Peter and the other disciples what they should do.
Peter doesn't hesitate to tell them. He knows that there is hope even for this crowd. He tells his hearers to repent and be baptized. They need to change their minds and their hearts (Greek metanoeō), to make an internal conversion, and then to be baptized, to receive the sacrament that cleanses them of all their sins and makes them new creatures in Jesus Christ. Then, Peter assures them, they, too, will receive the Holy Spirit. They, too, will know the truth and be able to speak it with confidence and clarity.
Next, Peter reminds his audience, that, as Jews, they are the recipients of God's promise. God has promised to send down the Holy Spirit on His people, on the Jews and their children, and Peter remarks, even on those who are “far off,” perhaps referring to the Gentiles. All they have to do is reach out and grasp God's gift with repentant and obedient hearts.
Peter ends by exhorting the crowd to “Save yourselves from this corrupt generation.” They have a prime opportunity right now to turn away from sin and to accept Jesus Christ and God's plan for humanity. They have a perfect chance to experience something life-changing, mind-changing, heart-changing, and eternity-changing if only they embrace Christianity and choose to follow Jesus Christ.
Many of Peter's hearers do just that. Three thousand are baptized that very day. Three thousand people begin a new life in Christ and all because Peter, guided by the Holy Spirit, is not afraid to tell it like it is.