What exactly is the gospel that Paul preached?

Les explains that Paul is defining the gospel he received by revelation: it is the message by which believers are saved, not something else, and they must keep in memory what Paul preached lest they believed in vain. Paul delivered first what he also received—that Christ died for our sins according to the Scriptures, was buried, and rose again the third day according to the Scriptures. Les stresses this gospel is not based on Judaistic law, nor merely on the fact that Christ was Israel's Messiah. Rather, the Messiah of Israel, the Son of God, died on the Roman cross, shed His blood, was buried, and rose again. His death was not an accidental martyrdom or a sudden stopgap; it was in God's pre-eternal plan according to the Scriptures. He was really dead, arose the third day, was seen by Peter and over 500, and was seen by Paul himself, proving He was alive.