Letters (Epistulae)

Therefore, when the Church was afflicted by these straits, whoever thinks that all things ought to have been endured rather than asking that God's help be brought through Christian emperors, pays too little attention to the fact that no good account could have been given for this negligence. V 19

For what they say, those who do not wish just laws to be instituted against their impieties, that the apostles did not ask for such things from the kings of the earth, they do not consider that the time was different then and that all things are done in their proper time. For who among the emperors had believed in Christ at that time, so as to serve Him by enacting laws for piety against impiety, when that prophetic saying was still being fulfilled:

"Why did the nations rage, and the people meditate on vain things? The kings of the earth stood up, and the princes met together against the Lord and against His Christ?" Ps 2:1-2

But that which is said a little later in the same psalm was not yet taking place:

"And now, O ye kings, understand; receive instruction, you that judge the earth. Serve the Lord with fear, and rejoice to Him with trembling." Ps 2:10-11

In what way, then, do kings serve the Lord in fear, except by prohibiting and punishing with religious severity those things which are done against the commands of the Lord? For he serves in one way because he is a man, and he serves in another way because he is also a king; for because he is a man, he serves by living faithfully, but because he is also a king, he serves by sanctioning laws that command just things and prohibit the contrary with appropriate vigor, just as Hezekiah served by destroying the groves and temples of the idols and those high places which were built against the commands of God. 4 Kgs 18:4