Paul tells us that, historically, the gospel was to go to the Jew first and then to the Gentile. And that is the program which is followed in the book of Acts. Soon it will turn to the Gentile world, for in Christ there is neither Jew nor Gentile; they all come on the same ground. But Peter's argument is, "Look, you are Jews. You know the prophets, you have been reading them. And your own Scriptures urge you to believe in Jesus." Peter brings it home with a personal emphasis: "God has sent him to you to turn you from your wickedness."
I wonder if Peter did not learn all this knowledge of the Old Testament application to the Christian life from what Jesus taught him during those forty days after his resurrection, when he opened their minds to understand the Scriptures and, "beginning with Moses and all the prophets, he interpreted to them in all the Scriptures the things concerning himself..." (Luke 24:27 RSV). Peter is really recounting those words here. And he is saying, "The final issue is this, and each of you must settle it for himself: Will you allow God to turn you from your wickedness?" Will you begin at the place where God begins -- not out at the periphery of life, clearing up a few surface problems, but right at the heart, with your problem of guilt,with your lack of acceptance of yourself before God, with your sense of inadequacy and inferiority -- and deal with that before Jesus Christ and, in the name of Jesus, believe that God loves you and receives you and makes you his own, and you are privileged to live as his child, his son, in the midst of this present life? That is where Peter leaves the issue. Perhaps you would like to answer this question Peter leaves with us: What are you doing with Jesus? Will you allow God to turn you from your wickedness -- in the name of Jesus?