Why did the twelve disciples not initially preach to the Gentiles?
The twelve initially focused on Israel because Israel's conversion was necessary before the times of refreshing and Christ's return as King. They were not yet concerned with evangelizing the whole world, but awaited Israel's national repentance to usher in the kingdom.
Les teaches that the twelve were not yet concerned about evangelizing the whole world. Their chief concern was the nation of Israel, because Israel had to be converted to the Last Man. The Holy Spirit was poured out on Jewish believers to continue confirming the message with signs, miracles, and wonders, so the nation would turn to their rejected Messiah. Peter's sermon in Acts 3:19-20 ties Israel's conversion to the times of refreshing, after which God will send Jesus Christ to be the King.