As they stretched him out to flog him, Paul said to the centurion standing there, “Is it legal for you to flog a Roman citizen who hasn’t even been found guilty?” – Acts 22:25 NIV
In the previous chapter Paul expressed his willingness to suffer and even to die for the name of the Lord Jesus. And he does suffer repeated and eventually dies for Christ. But here, just after enduring a beating at the hands of the Jews, he avoids a flogging at the hands of the Romans by claiming Roman citizenship. He was not afraid to use the law to save himself from an unnecessary beating.
The law of our land is not always advantageous for us as believers, nor should we really expect it to be. But when it is, there should be no problem with taking advantage of it, if it will serve to advance the gospel.