Whose responsibility was it to make the mystery known to the world?
The responsibility to make the mystery known to the world belonged to the Apostle Paul, formerly Saul of Tarsus. By revelation from the ascended Lord, the mystery was made known to him, and he then took the responsibility of passing it out to the whole world.
Les explains that Paul received the mystery by revelation from the ascended Lord in heaven—a revealed body of truth no one had ever before understood. It had been latent in the Old Testament but kept secret. After his conversion on the road to Damascus and three years in Arabia, Paul was prepared and skilled in what he proclaimed. Les teaches that Paul then took the responsibility of passing this revealed truth out to the whole world, including the Gentiles.