‘And when he had so said, there arose a dissension between the Pharisees and Sadducees, and the assembly was divided, for the Sadducees say that there is no resurrection, neither angel, nor spirit, but the Pharisees confess both.'
This immediately made the Pharisees wake up and concentrate on the case, and they then began to take up certain points that they had previously let slip by, recognising the truth in what Paul had drawn their attention to. They may have been sceptical about angels speaking to Paul but they were not sceptical about angels in general. They believed firmly in them. So they now argued that it was not reasonable to dismiss his claims simply on the grounds that angels did not exist. Perhaps angels had spoken to Paul. Who could tell?
This then led to dissension between the two sides as they argued the possibility of angels speaking at all, and whether the resurrection could occur. After all, Paul's defence, assuming that it was anything like that before the crowds, had included references to angels, and to the resurrection (note Acts 22:9-11 where this is made clear). So the truth or not of these questions was not a side issue, it was important. His case was bound to be dismissed by the Sadducees, who considered such things ridiculous, but surely it should not be viewed like that by the Pharisees? Surely they should give it more careful consideration.