What is the Gospel of the Kingdom, as Les defines it?
The Gospel of the Kingdom is the message that Christ was the King of Israel and was ready to give Israel the Kingdom, but they had to repent and be water baptized in order to be ready for that Kingdom.
Les explains that the Gospel of the Kingdom centers on Christ as the King of Israel, who was ready to give them the Kingdom. However, Israel had to repent and be water baptized to be ready for that Kingdom. In the context, Ananias is one of these, and Saul was coming after him and others like him. Later, Paul rehearses in Acts 26 that he thought he ought to do many things contrary to the name of Jesus of Nazareth, and he did them in Jerusalem against the saints, these Jewish believers.