What was the message of Peter and the 11 in the early chapters of Acts?
Peter and the eleven pleaded with the nation of Israel to recognize that the One they had crucified was the Messiah. That was the whole theme of the early chapters of Acts. Their message continued the appeal to Israel, leaving open the prospect that the nation could still receive the King and the Kingdom.
Les explains that after the crucifixion and resurrection, Jesus spent forty days appealing to the nation of Israel through primarily the twelve or the eleven. Then, as the early chapters of Acts open, Peter and the eleven continue to plead with the nation of Israel to recognize that the One they crucified was the Messiah. That is the whole theme in those early chapters. God had not canceled the nation of Israel, and everything was still within the prospect that they could have the King and the Kingdom, although Christ knew what they were going to do. At that point Judas was gone and Matthias was not yet in, so it was still only eleven.