Your rights

“But Paul said to the officers: ‘They beat us publicly without a trial, even though we are Roman citizens, and threw us into prison. And now do they want to get rid of us quietly? No! Let them come themselves and escort us out.’” Acts 16:37
Several times in the book of Acts we see Paul exercising his secular rights as a Roman citizen. Under Roman law, citizens were entitled to a fair trial. It was illegal for a Roman citizen to be flogged or beaten without a trial (see Acts 22:25-28). If the person felt the trial was unfair, they could appeal to have their case heard by Caesar (a right which Paul exercised in Acts 25:11).
Yet in 1 Cor. 9:11-15 Paul talks about the rights that an apostle should receive (namely, receiving sustenance as payment for his ministry), but then declares that he did not use this right, lest it cause a stumbling-block to the Corinthians. At the time there were many itinerant preachers, bringing a message to the people and ripping them off, and Paul did not want to be associated with those kinds of people.
The difference is this: in the first case, Paul was dealing with secular people and using his secular rights. There was nothing to be gained from not using them. But in the second case, Paul was dealing with spiritual people and talking about spiritual rights. His not exercising these would make a significant impact upon the Corinthians, and that alone was worth it.
Similarly for us: in the secular world, it’s ok to insist on your rights. But in the church, it is better to forego them if it would cause division or cause someone to stumble.