Romans 13:1-3 — Let every soul be subject unto the higher powers. For there is no power but of God: the powers that be are ordained of God.
Whosoever therefore resisteth the power, resisteth the ordinance of God: and they that resist shall receive to themselves damnation.
For rulers are not a terror to good works, but to the evil. Wilt thou then not be afraid of the power? do that which is good, and thou shalt have praise of the same.
The injunction to be in subjection to the higher powers, while important in every country, would have a special force in Rome, where the government would rigorously repress any religion which tended to run counter to that of the State, and especially Christianity, for Christians were larely regarded as a Jewish sect, and propaganda considered in any sense to be Jewish would be suspected as being of a revoltionary tendency.
These are the two great reasons for being subject to rulers. Civil authority is derived from God, and is arranged by Divine appointment. The first stresses the absolute supremacy of God, a supremacy which no adverse power can hinder or thwart. The second stresses the fact of God's power to exercise His authority in setting up and removing rulers. — W.E. Vine, The Epistle to the Romans, page 186.
1 Peter 2:13-14 — Submit yourselves to every ordinance of man for the Lord's sake: whether it be to the king, as supreme; or unto governors, as unto them that are sent by him for the punishment of evildoers, and for the praise of them that do well.
Daniel 4:17 — This matter is by the decree of the watchers, and the demand by the word of the holy ones: to the intent that the living may know that the most High ruleth in the kingdom of men, and giveth it to whomsoever He will, and setteth up over it the basest of men.
John 19:11 — Jesus answered, Thou couldest have no power at all against Me, except it were given thee from above: therefore he that delivered Me unto thee hath the greater sin.
power = freedom and authority to act
judgment — by rulers as authorized by God
This was written during the rule of Nero!, but it's referring to civil authority in its regular funtions, not persecution.
wilth thou, then … Isn't it reasonable to live so you have no fear of punishment by civil authority?
praise — from civil authority for being good.
Chapter 13 follows the injunctions in Romans 12:19-20 not to take your own vengeance.
Romans 12:1 instructs us to serve God as a spiritual service. Now we see that every soul should be subjected to the State.
We Christians are to be law-abiding citizens; but if governments forbid our preaching the Gospel, we will disobey and preach the Gospel. If governments order us to do evil, we will disobey. — Donald Grey Barnhouse, God's Discipline, page 107.