1) Special Revelation (which at the present time is limited to the Bible, though that was not always the case); and
2) General Revelation.
The light provided by special revelation on this issue is often quite clear: the just punishment for murder is death, for example (Genesis 9:6 Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man.).FN! Other times, the light is less clear - is the punishment for theft in the Mosaic economy the only just punishment or simply one just punishment out of several or perhaps the just punishment in that particular culture?
The light provided by general revelation is even less clear. Men's consciences are generally bothered by the idea of putting a simple thief (one who steals to feed his family) to death for his crime, and men are generally pricked in their conscience that it would not be proper to permit a rapist to escape with a fine amounting to less than the price of a postage stamp.
Nevertheless, we interpret the less clear by the more clear.
This is all old news, at least to me. Recently, however, I came across a most peculiar argument, and one that I thought I should address (argument by Ron Henzel found here):
[You] seem to be implying that any punishment for rape other than that prescribed by Moses would be arbitrary, and that for a Christian to support it would be inconsistent. I assume you would apply this reasoning to other criminal penalties as well.I found this line of argument most surprising.
But when Paul wrote, “Therefore whoever resists authority has opposed the ordinance of God” (Rom. 13:2), he was referring primarily to the Roman government, which had a different set of punishments than those prescribed by Moses. Even so, he referred to their authority as “the ordinance of God.”
Certainly, the laws of the Romans were to be honored by the people of the Roman empire. That is what Paul meant. But to convert such honor into an endorsement of the justice of the laws of the Roman empire would seem bizarre to me. The only rational justification would seem to be either that there is no objective standard of justice or that God providentially provides that every human government always is just. But Scripture - at least in the case of murder - seems to insist that there is an objective standard of justice. Furthermore, Paul himself notes that at least the Corinthian government was unjust (1 Corinthians 6:1) and Jesus in Luke 18 makes reference to an unjust judge.
So it would seem that the position that Mr. Henzel has presented lacks foundation.
In fact, if I had to guess at what was going on, I'd say that Mr. Henzel was overreacting to the label "theonomy," without considering (and accounting for) the undeniable facts that:
a) Justice is objective;
b) the Mosiac law was just both in identifying crimes as such and specifically in punishing them (Heb 2:2);
c) there is no other clear standard of justice; and
d) although Christians are to honor the king, that does not mean calling the unjust just, for we should be like the Proverbs 8:7 person: "For my mouth shall speak truth; and wickedness is an abomination to my lips."
Zechariah the prophet declared the following, which I think applies not only to Jerusalem of his day, but also to Christian democracies (and democratic republics):
15So again have I thought in these days to do well unto Jerusalem and to the house of Judah: fear ye not. 16These are the things that ye shall do; Speak ye every man the truth to his neighbour; execute the judgment of truth and peace in your gates: 17And let none of you imagine evil in your hearts against his neighbour; and love no false oath: for all these are things that I hate, saith the LORD.
FN1 It is important to note that capital punishment for murder preceded the Mosaic economy, and consequently cannot reasonably be thought to be a law that was intended to be limited to the Jewish nation.