There are two brave statements in this passage. I can learn from each of them.
Peter and the apostles affirm that if the choice is clearly about following man or following God, they will follow and obey God. The apostles had a very clear message and I think this made their choice simple. They were certain of the fidelity of their cause. For me then, I must weigh the purity of my case. This means prayer and seeking God’s face.
The second brave statement comes from Gamaliel. He is a man of great wisdom. I think he is actively following God rather than man too. He affirms the God will have His way and will not be thwarted. He affirms a course of purity by submitting that he and the others might not really know the best answer. In doing so He honors God in waiting for God to reveal His own way.