Mark 12:17

And Jesus said unto them, Render unto Caesar the things that are Caesar's, and unto God the things that are God's. And they marveled greatly at him.

Render unto Caesar the things that are Caesar's ... is the basis of the Christian's concept of the state and his obligations to the secular government. The principle uttered here by the Lord was elaborated by the apostles in Romans 13:1-7; 1 Timothy 2:1-6; and 1 Peter 2:13-17. For an essay on "The Christian's Relation to the State," see my Commentary on Romans, Romans 13.

And unto God the things that are God's ... This is a higher theater of obligation; and the Christian may not violate the commandment of God, regardless of any edict published by the state; and in the most extreme conflict between God and Caesar, the Christian must not hesitate to die rather than violate the law of God. The death of all the martyrs is a testimony to the validity of this principle.

And they marveled greatly at him ... No wonder. Men of all ages have marveled at what the Son of God taught in this passage. He brushed aside their silly little dilemma, as a man might brush off a mosquito, and proceeded to lay down laws which have governed and enlightened men of all succeeding ages.