Bible Scholars have called Paul's speech before King Agrippa in Acts 26 the “climax of all Paul’s speeches in Acts” and the summary of the book of Acts’ Christology (Ben Witherington). In it Paul makes his defence, and in the process sets out a bold and clear summary of the gospel he has preached during his missionary journeys.
So, what is the gospel that Paul preached?
1. The death and resurrection of Jesus Christ according to the Old Testament Scriptures.
"...and so I stand here testifying both to small and great, saying nothing but what the prophets and Moses said would come to pass: that the Christ must suffer and that, by being the first to rise from the dead, he would proclaim light both to our people and to the Gentiles.” Acts 26:22b-23, ESV
This agrees with Paul's review of his gospel in his letter to the Corinthians:
"Now I would remind you, brothers, of the gospel I preached to you, which you received, in which you stand, and by which you are being saved, if you hold fast to the world I preached to you - unless you believed in vain. For I delivered to you as of first importance what I also received: that Christ died for our sins in accordance with the Scriptures, that he was buried, that he was raised on the third day in accordance with the Scriptures, and that he appeared..." 1 Corinthians 15:1-5a, ESV
This is the content of the gospel (good news) that Paul preached. But he also preached what our response should be:
2. Salvation Is Through Faith In Jesus.
"I (Jesus) am sending you to open their eyes, so that they may turn from darkness to light and from the power of Satan to God, that they may receive forgiveness of sins and a place among those who are sanctified by faith in me.’" Acts 26:17b-18, ESV
Jesus made it clear to Paul that those who would be sanctified (set apart to Jesus as his people) and those who would be forgiven of their sins are only those who have "faith in" Jesus.
3. We Must Repent of Sins.
"I was not disobedient to the heavenly vision, but declared first to those in Damascus, then in Jerusalem and throughout all the region of Judea, and also to the Gentiles, that they should repent and turn to God..." Acts 26:19b-20a, ESV
Here Paul says he preached repentance of sin and turning to God. This is repentance and faith working together. As we turn away from our false gods, idols and sins, we must turn toward something else. That is where faith comes in, and faith must have an object. Paul did not preach faith in general, but faith in Jesus Christ, who died for our sins and rose again. The gospel Paul preached included a call to forsake other gods and all sins, turning from these things and practices, and embrace Christ and his death and resurrection as the Way to the one true God.
4. We Must Continue In Faith and Repentance, Bearing Fruit.
"that they should repent and turn to God, performing deeds in keeping with their repentance." Acts 26:20b
Paul was clear that our works do not save us, but that works must be present as proof of our genuine conversion. An absence of works reveals a false faith that does not save. This is why he wrote to the Corinthians (quoted above), that they were saved by the gospel he preached, "if you hold fast to the world I preached to you - unless you believed in vain (1 Cor 15:2).
Paul made this clear to the Ephesian believers as well:
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them." Ephesians 2:8-10, ESV
Paul says that salvation is not a result of works, but then he says that we were created in Christ Jesus for good works. God has even prepared this for us beforehand, that we should walk in these good works as a continual lifestyle. They do not earn our salvation, but will be present after our conversion. Christ changes our life!
This is the gospel that Paul preached, which he received from Jesus Christ himself as he was converted on the road to Damascus. This is THE gospel. Is it the one you have believed? Is it the one you preach?