It's an open question for me how much truth there is in Paul's teachings, and in the doctrines of today's Christian churches, about salvation. It's an open question for me whether the gospels were first written before or after the letters of Paul. However that may be, I don't see anyone disagreeing with saying that in the gospels, Jesus talks much, much more about recognizing and accepting Him as a person to serve and obey and about learning to live the way He says to live, than He does about His death and resurrection and their significance, and He calls His gospel "gospel of the kingdom," not "gospel of salvation."