Acts 5:29 (NIV)
Peter and the other apostles replied: "We must obey God rather than men!
Acts 5:38b-39 (NIV)
...Leave these men alone! Let them go! For if their purpose or activity is of human origin, it will fail. But if it is from God, you will not be able to stop these men; you will only find yourselves fighting against God.
The Sanhedrin ruling class in Jerusalem wanted to silence Peter and the apostles. I love how they replied that for them, obeying God rather than men was mandatory. We find that when the church was most persecuted was when it grew the most.
I like how one of the wiser rulers concluded his discussion of the issue, a human endeavor is doomed to failure but one that originates from the will of God cannot fail. This is why when we pray in the will of God, we know that our prayers will be answered.