A Christian should always obey and respect national laws because “the authorities are appointed by God” (Romans 13:1-5).
Nevertheless, in the very rare case that a government passes a law that goes against God’s laws (for example, if we are ordered to worship idols, or to join the army) then we must “obey God rather than men”. (See Acts 5:29).
A Christian should not take his brother to law. (1 Corinthians 6:18).