"But Peter and the other apostles answered and said, 'We ought to obey God rather than men. The God of our fathers raised up Jesus whom you murdered by hanging on a tree. Him God has exalted to His right hand to be Prince and Savior, to give repentance to Israel and forgiveness of sins. And we are His witnesses to these things, and so also is the Holy Spirit whom God has given to those who obey Him'" (Acts 5:29-32).
Once again Peter and the apostles respond with boldness. They remind the council that they were obligated to obey God rather than men, and, since God had instructed them to preach, they would continue doing so (no matter who forbid them!). Christians always have a primary obligation to God first (cf. Matt. 6:33). This principle is applicable in all contexts (e.g., at work, at home, in the church, as a citizen, etc.). Peter also acknowledges that the second charge is true. He courageously calls them murderers right to their faces! But God showed their deed to be wicked and Jesus to be innocent. Jesus, as our Prince (leader) and Savior, was raised from the dead by God in order to make repentance and remission of sins available to the world. The apostles affirmed that they were witnesses of these truths; they were not idle dreamers who had invented a new religion. God would only give supernatural power (in this context, the "Holy Spirit") to those who were obedient. Thus, the miracles they were working and their marvelous delivery from a guarded prison were proofs of their testimony. God was pleased with them!
"When they heard this, they were furious and plotted to kill them. Then one in the council stood up, a Pharisee named Gamaliel, a teacher of the law held in respect by all the people, and commanded them to put the apostles outside for a little while. And he said to them: 'Men of Israel, take heed to yourselves what you intend to do regarding these men. For some time ago Theudas rose up, claiming to be somebody. A number of men, about four hundred, joined him. He was slain, and all who obeyed him were scattered and came to nothing. After this man, Judas of Galilee rose up in the days of the census, and drew away many people after him. He also perished, and all who obeyed him were dispersed. And now I say to you, keep away from these men and let them alone; for if this plan or this work is of men, it will come to nothing; but if it is of God, you cannot overthrow it--lest you even be found to fight against God.' And they agreed with him, and when they had called for the apostles and beaten them, they commanded that they should not speak in the name of Jesus, and let them go" (Acts 5:33-40).
Not surprisingly, the continued boldness and "rebellion" of the apostles was not well-received by the Sanhedrin. They are angry enough to kill them! One Pharisee of the council, Gamaliel, who was highly regarded, had some thoughts he wanted to share with the other members privately (before they acted rashly). After the apostles are excused momentarily, Gamaliel presented a history lesson of a couple recent movements. He noted that when leaders gather a large following (e.g., like Theudas or Judas of Galilee) that after they die their followers are typically dispersed. The exception he noted was that if the movement was "of God" then it would continue and could not be overthrown in any way (cf. Dan. 2:44). Gamaliel exhorts the council to stay away from the apostles and just leave them alone. This Christian movement would die out on its own if it was the work of men, but otherwise, if it was a work of God, then the council could not stop it even if they killed the apostles (and they would be fighting against God in such a case!).
Although the enraged Sanhedrin claimed to agree with Gamaliel's advice, they still beat the apostles severely (similar to the scourging Jesus received; cf. Matt. 10:17). After commanding them again to cease preaching Jesus, they let them go. The lashes would have left them bleeding and torn, and unable to forget the order from the Sanhedrin to be silent!
In the providential scheme of things, Gamaliel can be credited with saving the lives of the apostles. However, we must be careful not to draw a conclusion from his words that would contradict what is revealed in the rest of the New Testament. It is true that when one opposes God's people, he makes himself an enemy of God Himself. But, it is not true that a false religious movement should simply be ignored forever. False doctrine is to be exposed and truth upheld (cf. Jude 3; II Tim. 4:2; Eph. 5:11). Merely because a particular doctrine or religious group lasts a long time does not mean that such is approved by God!