At Mark chapter 1 verse 14 Jesus came preaching the gospel of the kingdom. Is this the same gospel that Paul preached in 1 Corinthians 15?
Regardless of what you might hear, there is only one gospel, and it’s for everyone. Paul claimed to have been taught the gospel directly by Jesus (Galatians 1:11-12) and summarized what he learned in 1 Cor. 15:3-4
“For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures.”
In 1 Cor. 15:11 he also said it was the same gospel preached by the other apostles.