Gamaliel"s point was that if God was not behind the apostles their efforts would prove futile in time. Obviously Gamaliel believed this was the case or he would have become a Christian. He offered the theoretical option that if the apostles were of God the Sanhedrin would find itself in the terrible position of fighting against God. Obviously Gamaliel believed in the sovereignty of God. He advised his brethren to wait and see. He did not believe that the apostles presented as serious a threat to the leaders of Judaism as the Sadducees believed they did. Saul of Tarsus took a different view of how the Jews should respond to the growing threat of Christianity. He executed many Christians, but that was after the number and influence of the Christians had increased dramatically (cf. chs6-7). [source][source][source]
"The point made ... by Gamaliel ... has already been made by the narrator through the rescue from prison and the ensuing scene of discovery. Here we have an instance of reinforcement through reiteration. A message is first suggested by an event and then clearly stated in the interpretive commentary of a story character." [1][source]
Gamaliel"s counsel helps us understand how objective unbelieving Jews were viewing the apostles" claims at this time. There had been others beside the apostles who had insisted that their leaders were great men. Yet their claims had eventually proved false. Many of the Jews, whom Gamaliel represented, likewise viewed the apostles" preaching as well-meaning but mistaken. Jesus was no more special than Theudas or Judas of Galilee had been. Other than their ideas about Jesus being the Messiah, the apostles held views that did not challenge fundamental Pharisaic theology. However the disciples, like Jesus, rejected the authority of oral tradition over Scripture. [source][source][source]