Some say that Paul never proclaimed the kingdom of God, but preached only the mystery. What is the evidence?
Paul was told first of all by the risen Lord to preach the things which he had seen (Acts 26:16). What he had seen was what the 12 and others were doing. So if Paul preached only the mystery, then we will have to say the same of the 12 and also of Stephen whom Paul heard. In Acts 17:7 the men of Thessalonica heard Paul preach and reported that he preached another King instead of Caesar. Evidently Paul was preaching the kingdom, the same as the 12, up to Acts 28:28.