What secret did Jesus know about Israel and the Gentiles at the time of Acts 1?
At Acts 1, Jesus knew that Israel would reject the kingdom and that He would turn to the Gentiles under a whole different program. This was a secret not yet revealed; only the timing of the kingdom was withheld from the disciples.
Les teaches that Jesus and the eleven were still on the Mount of Olives discussing things pertaining to the kingdom. That kingdom was valid and real, not a figment of their imagination. The only thing Jesus said was not for them to know was the timing. He also knew that Israel would reject all this and that He would be turning to the Gentiles under a whole different program. But that was secret; He had not revealed it yet. Les explains that God has the prerogative to keep things secret until He is ready to reveal them.