Who is the authority through whom God speaks to believers in this age of grace?

Les teaches that Paul opens by declaring himself "called to be an apostle," which is almost identical with the openings of all his other letters. The first thing Paul had to establish to whomever he wrote was the authority connected to his apostleship. Les explains that for believers in this age of grace, Paul is the authority through whom God is speaking to the whole human race. Paul was always defending that apostleship, especially to the Jewish people, because they thought he was a renegade to Judaism and had turned on his background. Les also notes that the Corinthians had divisions, with some saying they followed Paul, others saying they listened to Peter, and still others saying they did not care what Paul said but would do what Jesus said. Yet Paul had to establish that now, for believers in this age of grace, he is that authority.