Why didn't Paul use his Jewish background when preaching in Corinth?

Les explains that Paul did not even rehearse all his Old Testament knowledge, though he could have. At Corinth—described as a wild, wicked, Gentile city—God did not permit Paul to use his Jewish background. Paul came with only one message, the gospel that is almost forgotten today: that Christ died for the sins of the world, that He died for me and for you. Les laments that this simple message is often circumvented and that people come close but do not hear it plainly. He illustrates this with a funeral sermon where the preacher was eloquent but, at the threshold of the plan of salvation, dropped the ball and failed to preach Christ crucified.