What was the whole theme of the early chapters of Acts?
The whole theme of the early chapters of Acts was Peter and the eleven pleading with the nation of Israel to recognize that the One they crucified was the Messiah. God had not canceled Israel, and the King and Kingdom were still prospectively offered, though Christ knew their response.
Les explains that after the crucifixion and resurrection, Jesus spent 40 days appealing to the nation of Israel through primarily the twelve or the eleven. Then, as you come into the early chapters of Acts, Peter and the eleven continue to plead with the nation of Israel to recognize the One they crucified was the Messiah. That is the whole theme in those early chapters. So God had not yet canceled the nation of Israel, and everything was still within a prospect at least that they could have the King and the Kingdom, although Christ of course knew what they were going to do.