The gospel that Paul preached was unique. Rom 2:16; 16:25. Paul referred to it as “my gospel.” It was the “gospel to the uncircumcision.” Read all of Galatians chapter 2. It is still the good news gospel to Christians today. No one preached it before Paul. Peter, James and John did not preach it until after Paul. See Gal 2 and 2 Pet 3:14-16. Paul called it the “preaching” or “message” or “word” “of the cross.” 1 Cor 1:17-18; 2:2. This story of the cross turned the world, like the cake, upside-down.
Paul’s revelation was received direct from the risen Christ (Gal 1:12) turned the entire religious world, including both Judaism and the Jewish Believers in Christ, on its head. It said we are not to climb up but rather to surrender, to let go and fall into God’s grace, descending into a death, burial and resurrection participation with Christ. Rom 6:3-5; Phil 3:10; Gal 2:20; 2 Cor 4: 7-18; 2 Cor 15:14-15.