Galatians 1:11 But I certify you, brethren, that the gospel which was preached by me is not according to man. 12 For I neither received it from man, neither was I taught it, but by the revelation of Jesus Christ. Webster’s Bible Translation
So what is the Gospel that Paul is preaching? Acts 13:16-41 gives us an example of apostolic preaching as this is where we see the history of the first missionary journey of Paul and Barnabas.
Acts 13:16 Paul stood up, and beckoning with his hand said, “Men of Israel, and you who fear God, listen. 17 The God of this people Israel chose our fathers, and exalted the people when they stayed as foreigners in the land of Egypt, and with an uplifted arm, he led them out of it. 18 For a period of about forty years he put up with them in the wilderness. 19 When he had destroyed seven nations in the land of Canaan, he gave them their land as an inheritance. 20 And after these things, about four hundred and fifty years, he gave them judges, until Samuel the prophet. 21 Afterward they asked for a king, and God gave to them Saul the son of Kish, a man of the tribe of Benjamin, for forty years. 22 When he had removed him, he raised up David to be their king, to whom he also testified, ‘I have found David the son of Jesse, a man after my heart, who will do all my will.’ 23 From this man’s offspring, according to his promise, God has brought to Israel a Savior, Jesus, 24 before his coming, when John had first preached the baptism of repentance to all the people of Israel. 25 As John was fulfilling his course, he said, ‘What do you suppose that I am? I am not he. But look, one comes after me the sandals of whose feet I am not worthy to untie.’ NHEB
Paul’s audience is both Jewish and Gentile (the God-fearers). Paul begins in the Old Testament with the patriarchs and the deliverance of God’s people out of Egypt. Despite the complaining and grumbling for the forty years they were in the wilderness, He remained their God.
Acts 13:26 Brothers, children of Abraham, and you Gentiles who fear God, it is to us that this message of salvation has been sent. 27 The people of Jerusalem and their rulers did not recognize Jesus, yet in condemning Him they fulfilled the words of the prophets that are read every Sabbath. 28 And though they found no ground for a death sentence, they asked Pilate to have Him executed. 29 When they had carried out all that was written about Him, they took Him down from the tree and laid Him in a tomb. 30 But God raised Him from the dead, 31 and for many days He appeared to those who had accompanied Him from Galilee to Jerusalem. They are now His witnesses to our people. BSB
In Acts 13:26, salvation is another word for deliverance. “Carried out all that was written” means the Old Testament.
We typically think of the Gospel as something God has done for us so the Old Testament references may be a little surprising. Paul understands that the Old Testament is full of Gospel as Gospel is the premise of the Jewish religion. Passover, for example, is a story of grace. Same for deliverance out of bondage in Egypt. Jesus is the fulfillment of those promises.
Acts 13:32 And now we proclaim to you the good news: What God promised our fathers 33 He has fulfilled for us, their children, by raising up Jesus. As it is written in the second Psalm: ‘You are My Son; today I have become Your Father.’ 34 In fact, God raised Him from the dead never to see decay. As He has said: ‘I will give you the holy and sure blessings I promised to David.’ 35 So also, He says in another Psalm: ‘You will not let your Holy One see decay.’ 36 For when David had served God’s purpose in his own generation, he fell asleep. His body was buried with his fathers and saw decay. 37 But the One whom God raised from the dead did not see decay. 38 Therefore let it be known to you, brothers, that through Jesus the forgiveness of sins is proclaimed to you. 39 Through Him everyone who believes is justified from everything you could not be justified from by the law of Moses. 40 Watch out, then, that what was spoken by the prophets does not happen to you: 41 ‘Look, you scoffers, wonder and perish! For I am doing a work in your days that you would never believe, even if someone told you.’” BSB
When Paul quoted verses, people knew the full reference he was making. We see death, burial, Resurrection and now forgiveness proclaimed. Everyone who believes is justified but, there is a response required.
Paul’s opponents say he is wrong because he wasn’t part of the original team but that presupposes that all that matters in the New Testament are the words marked in red. The work and influence of Jesus didn’t stop with His death – it continued afterward through the Holy Spirit in the works and teachings of the apostles. Paul was with the risen Christ and is now sharing what he learned from his time with Jesus. It might be helpful to think of it in the way that John Calvin did with the Gospel accounts being before resurrection and the epistles being after resurrection.
Galatians 1:13 For you have heard of my former way of life in Judaism, how I severely persecuted the church of God, and tried to destroy it. 14 I advanced in Judaism beyond many of my own age among my countrymen, being more exceedingly zealous for the traditions of my fathers. 15 But when God, who had set me apart from my mother’s womb and called me through his grace, was pleased 16to reveal his Son to me, that I might proclaim him among those who are not Jewish, I did not immediately confer with flesh and blood, 17nor did I go up to Jerusalem to those who were apostles before me, but I went away into Arabia. NHEB
In his earlier days, Paul thought the idea of Christ was blasphemous and as a zealous Jew, went out of his way to try and kill the church and persecute its believers. Paul was serious enough about his Jewish faith to study under Rabbi Gamaliel in what would be the equivalent of a seminary education today. (Gamaliel was the person who advised caution to the Sanhedrin in Acts 5 where John and Peter are standing trial).
Given all of this history, Paul is not exactly the ideal candidate for this office he now holds, but God had other ideas by setting him apart for the job. At first blush, the plan that God has for Paul’s life in verse 15 might appear to be related to predestination. We know that God has a sovereign plan that works through history but this reference appears to be an election for purpose, like David or Mary rather than an election to salvation.
Philippians 3:3 For we are the circumcision, the ones who worship by the Spirit of God, exult in Christ Jesus, and do not rely on human credentials 4– though mine too are significant. If someone thinks he has good reasons to put confidence in human credentials, I have more: 5 I was circumcised on the eighth day, from the people of Israel and the tribe of Benjamin, a Hebrew of Hebrews. I lived according to the law as a Pharisee. 6 In my zeal for God I persecuted the church. According to the righteousness stipulated in the law I was blameless. 7 But these assets I have come to regard as liabilities because of Christ. 8 More than that, I now regard all things as liabilities compared to the far greater value of knowing Christ Jesus my Lord, for whom I have suffered the loss of all things – indeed, I regard them as dung! – that I may gain Christ, 9 and be found in him, not because I have my own righteousness derived from the law, but because I have the righteousness that comes by way of Christ’s faithfulness – a righteousness from God that is in fact based on Christ’s faithfulness. 10 My aim is to know him, to experience the power of his resurrection, to share in his sufferings, and to be like him in his death, 11 and so, somehow, to attain to the resurrection from the dead. NET