In the thirteenth and fourteenth chapters of Romans is one of the strongest of the many strong treatises that there are in the Bible upon the total separation of religion and the State -- the separation between that which is due to God and that which is due to Caesar.
First is a recognition of the right of the State to be, and to require subjection and tribute: "Let every soul be subject to the higher powers." "The powers that be are ordained of God." "For this cause pay ye tribute also." "Render therefore to all their dues: tribute to whom tribute is due; custom to whom custom; fear to whom fear; honor to whom honor" (Rom. 13:1-7).
Next is marked the sphere of men's relation to the State: "Owe no man anything, but to love one another; for he that loveth another hath fulfilled the law. For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbor as thyself" (Rom. 13:8, 9).
Now everybody knows, and Paul knew as well as anybody ever knew, that there are other commandments -- other commandments of the very law from which he quoted these.
There is the commandment: "Thou shalt have no other gods before Me. Thou shalt not make unto thee any graven image; . . . thou shalt not bow down thyself to them, nor serve them; for I the Lord thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate Me; and showing mercy unto thousands of them that love Me, and keep My commandments. Thou shalt not take the name of the Lord thy God in vain." "Remember the Sabbath day, to keep it holy. Six days shalt thou labor, and do all thy work; but the seventh day is the Sabbath of the Lord they God; in it thou shalt not do any work; . . . for in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day; wherefore the Lord blessed the Sabbath day, and hallowed it" (Ex. 20:3-11).
With these commandments standing as a part, and, indeed, the first part, of the very law which he was citing, why did he leave these entirely out and say, "If there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbor as thyself"? Why? -- For the simple reason that he was writing of men's relationship and responsibility to the powers that be, to the State; and he was laying down the principle that when men have recognized the right of the State to be, have paid the required tribute, and have fulfilled all obligations to their neighbors, there is nothing more for them to render to the State; there is no other commandment in that sphere, and therefore no other duty to be performed toward the powers that be.