John Calvin Commentary Acts 25:11

"If then I am a wrong-doer, and have committed anything worthy of death, I refuse not to die; but if none of those things is [true] whereof these accuse me, no man can give me up unto them. I appeal unto Caesar." — Acts 25:11 (ASV)

I appeal to Caesar. After he has professed that he does not refuse to die if he is found guilty, he freely uses such help as he could find from men. Therefore, if we are at any time brought into similar difficulties, we must not be superstitious, but we may seek help from the laws and civil order. For it is written that magistrates are made and appointed by God for the praise of the godly (Romans 13:3; 1 Peter 2:13). Neither was Paul afraid to go to law under an unbelieving judge, for he who appeals commences a new action.

Therefore, let us know that God, who has appointed judgment seats, also grants liberty to His people to use them lawfully. Therefore, those are mistaken who think that Paul flatly condemns the Corinthians (1 Corinthians 6:1) because they require help from the magistrate for the defense of their right, since he reproves in that passage a manifest fault: namely, that they could suffer no wrong and were too much set upon suing one another, by which they caused the gospel to be spoken evil of.