I said earlier that Paul’s sermon is not only like that of Stephen before the Sanhedrin in its review of Old Testament history. It is also like that of Peter at Pentecost in its citation of Old Testament texts. This is what Paul does in the third part of the sermon, beginning in verse 32.
3. A selection of supportive biblical texts. There are four texts here, and all of them are Old Testament support for or further explanation of what God accomplished in the incarnation and work of Jesus Christ.
The first text is Psalm 2:7 (“You are my son; today I have become your Father”). Here God the Father is speaking to God the Son, and Paul rightly sees this as having been written of Jesus.
The second text is Isaiah 55:3 (“I will give you the holy and sure blessings promised to David”). This text fits Paul’s sermon well, for he has been trying to show that the promises made to David are fulfilled in Jesus.
The third text is Psalm 16:10 (“You will not let your Holy One see decay”). Peter used this same text in Acts 2:25-28, pointing out, as Paul does, that it was written of the Messiah, who, though He died and His body was buried, did not decay. Rather His body was preserved, and He was raised again on the third day.
The fourth text occurs in the final part of the sermon, beginning with verse 38. It is Habakkuk 1:5 (“Look, you scoffers, wonder and perish, for I am going to do something in your days that you would never believe, even if someone told you”).
4. An announcement of the Gospel. Everything that has been said up to this point leads to an announcement of the Gospel and a plea for personal response: “Therefore, my brothers, I want you to know that through Jesus, the forgiveness of sins is proclaimed to you. Through him, everyone who believes is justified from everything you could not be justified from by the law of Moses” (vv. 38-39).
Someone has pointed out that “justification” means “just as if I’d never sinned.” That is exactly right. It is not that you and I have never sinned, because we have. It is rather that, because of the work of Jesus Christ, who bore the punishment of our sin in our place, we can now stand before God as if we had never sinned—that is, as if we were Adam or Eve before the fall. Paul says the law could never do that. He mentions the law because he was speaking in a synagogue to those who loved the law and based their hopes of salvation upon keeping it. He knows whereof he speaks. He tried to live like that himself at one time. In those days he thought he was keeping God’s law perfectly (Phil. 3:6). But when he met Jesus on the road to Damascus he learned that the law actually condemned him, since he was not keeping it, and that if he were to be saved it would have to be by Jesus doing for him what the law could not do. In Christ, God atoned for sins committed and provided a basis on which he could justify sinners.
That is the good news Paul came to Galatia to proclaim. It is precisely what swept through Europe and transformed the world.
But notice that, although the Gospel is indeed good news—in fact, the best news the world has ever heard—Paul does not end with good news but with a warning. It is where the quotation from Habakkuk comes in. “Take heed that you do not neglect this Gospel,” Paul says. Why? Because, although ours is an age of great grace, God is nevertheless also a God of great judgment, and sin must be judged if it is not atoned for by the work of Christ. The text from Habakkuk concerns the fall of Jerusalem, which was an expression of God’s judgment upon Israel. On that occasion God judged His Old Testament people. Will He not also judge those who, living in the New Testament period, reject His offer of forgiveness through the work of Christ?
Remember that the Old Testament God and the New Testament God are one and the same. Therefore, if you will not have forgiveness of your sins through Jesus Christ, the wrath of God will come upon you. When Paul finished his sermon, there was interest on the part of the people. They invited the apostles to return the next Sabbath and speak about Jesus further.
Some of these people undoubtedly believed in Jesus Christ eventually and presumably became active in promoting the Gospel throughout this region of Asia. But at this point they still seem to have a way to go before they truly became Christians. They had to repent of their sin and trust Jesus for their salvation. Yet they were interested. They wanted to hear more, and many followed after Paul and Barnabas asking questions. I wonder if you are as interested in the Gospel as they were even at this early point. It is possible that you may go to church regularly, hear the same good news over and over, but then yawn your way home, saying, “Oh, yes, that; I’ve heard that before.” You have heard it, but it has left you unchanged. Don’t allow that to happen. Listen to the Gospel, but also respond to it. Turn from your sin and come to Jesus Christ as your Savior.