It's not very meaningful either to sit here in 21st century North America and pontificate about what historical personalities - focusing uniquely on them and not on their times also - 'should have done'.
It is very meaningful, because it shows us how men get tangled up in the politics and passions of their times, and ending up committing heinous evil that he should have known not to commit given Jesus' clear and explicit two-thousand year old directions.
And that can instruct us now, today, in the passions of our own times over things such as infanticide, abortion, war, slavery, segregation, freedoms of speech, police violence and abuse, prison policies - everything. There is very little new under the sun. All of the past generations have dealt with almost all of these issues before. Jesus gave us a clear and unambiguous set of hard stops as to where we as individuals, whether private, uniformed or crowned, may never go.
The problems of the world are intractable, and human beings are stubborn. Most will not obey without the threat of loss, and the threat of loss can only be backed up by the ultimate threat of violence. So, then, the question becomes "Can man be rightly ruled by the threat of violence?"
And the answer to that from Jesus is that if you actually resort to the violence and kill people, and never repent it and seek forgiveness from God, he is going to judge you without mercy and throw you into the Lake of Fire at final judgment.
So yes, in the present tense we BETTER understand the sins of Justinian and Cauvin and the Popes and the police and rulers past and present, and the Apostle Paul also - he was an evil killer. PAUL repented, and was saved by Jesus. Did Justinian, Cauvin, or the Popes ever repent? Did they ever admit that they willfully overrode the law of Jesus in their own anger at being disregarded, and murdered men in order to cow other men into submission? Did they ever admit they were murderous worms, the worst of all sinners? Paul did, and for the very reasons stated: he pursued Christians unto death. Paul was a vicious disgusting wretch of a man, before his conversion, and there was no particular reason why people who had lost friends and relatives to him as a marauder should have ever trusted him again. After all, in our day the priests in Eastern European confessionals were KGB spies.
We know that Paul got right with God, so we can listen to him. But he had to repent or he was headed to the Lake of Fire.
HE repented. I don't really care if Cauvin did or didn't.
But Cauvin matters today because he is a "type" of ruler. See the enraged cops beating mentally disabled people to death because of their "non-compliance"? What do WE think of that? What do we do about it?
What about the murder of babies in the womb?
What about Middle Eastern wars?
The same frustrating issues face every generation, and the temptation to reach for the sword is great. It is highly instructive to look at the catastrophic moral failures and disasters wrought by the great leaders of historical Christianity.
And yes, they were governed by the same moral code we are, from the same source: Jesus.
This is the problem. Cauvin wasn't some King. He stood as the spiritual leader and teacher. It is absolutely correct to judge his moral code, because it is the SAME AS OURS - because both he and we are bound by Jesus.
There were people in his day who would never do what he did. There are people in our age that would justify it and do it. Looking at the moral issues and the questions of power and violence is a separating of the sheep and goats, exactly as Jesus will do at the end. By looking at it, if we are on the borderline, as many of us our, we can be encouraged to be good sheep, and not give ourselves over to rage in our frustration that the world sucks as bad as it does, and become goats.
What Cauvin did is relevant to today, and both he and you and I will be judged by EXACTLY THE SAME STANDARD - the one that Jesus, the master of all of us, set a millennium and a half BEFORE Cauvin.
To drive the point home even more fully: people TODAY hang their Christian religion on what Cauvin wrote, as a teenager, in a second-rate provincial French law school. Cauvin's first Institutes were written when he was a teenager. He revised and extended them, but the first edition was published by a teenager. People are basing their concepts of God himself, in the 20th Century, on the ideas in the head of a 19 year old second-rate law student, who went on to be an aggressive Christian Taliban.
Who Cauvin was, when he wrote what we wrote, and what he went on to do under the emprise of his own thoughts, are all a very strong warning THIS IS THE WRONG TRACK. The only way to realize that is to know the history.
Follow Cauvin's approach today, and if you get in charge of anything you're likely to end up in front of a war crimes tribunal.
Which MEANS that there is something wrong with his Christian theology, and people should not be following it. That's EXACTLY the implications of it.
Similarly, the fact that the Catholic Church BURNT ALIVE a messenger of God means that the supreme claims of infallibility and imperfection have to be taken with a shaker of salt. No, dear, you're not imperfect. You've been really terribly imperfect. If you hadn't reformed yourself you would really be an enemy of mankind, and our ancestors were right to decapitate your power and reduce you to a private religious institution, because when you were in charge, you were a dragon who did immense evil.
As a nice old lady without a sword, the Church is quite creditable, but the Church that burnt Joan of Arc, after official trial, in Rouen, was a violent and direct enemy of God, at least in that place and that time. Which means that she lost the ability to claim the she is without error for ALL TIME everafter. The same is true of Cauvin. BECAUSE he was in power, and executed people for heresy, his theology is fundamentally flawed. If you're killing people in the name of Christ, your theology is bad and you are to be disregarded, for all time.
Paul is the least of the apostles BECAUSE he was a killer. He is an example of the great fruit born from a repentant soul. Did Cauvin EVER publicly repent? The Catholic Church in that age did not. In OUR age it has repented many of the crimes of the past, though it still impossibly asserts that it is nevertheless without error or stain - by creating a mystic Church that abides somewhere else, wholly detached from humanity. That's a nice story, and if we need to believe that, fine, but we cannot justify the burning of Joan of Arc, or anybody, and the fact that it happened so often MEANS that no pronouncement of any religious leaders can be accepted as infallible on its face. Rather, the SUBSTANCE of the pronouncement has to be examined.
And when it comes to directing the killing of people, nothing is simpler: the man and the institution ordering it are wrong, and evil, and not to be obeyed in the order, or emulated as a role model. Jesus promises to throw them into the flames at final judgment too, so all we can do is urge such people to REPENT.
To do that, we have to admit they were wrong.
And yeah, the wrongs of the past matter today. If they didn't, then all of Christendom could unite as one and feed the poor without all of this duplication of administrative expense in multiple clergies.