I'm going to begin by quoting some statements by Arminian theologian Roger Olson:
Few movies have affected me as strongly as the 2011 film “Machine Gun Preacher” starring Gerard Butler as Sam Childers, drug addict turned Christian missionary who takes up an AK-47 for Jesus in the Sudan. Based on Childers’s true life story, the movie raises gut-wrenching questions about Christian ethics and especially whether use of deadly force is ever justified for the Christian. As those who have seen the movie know, Childers joined a mission trip to the Sudan and there encountered children being slaughtered and forced to kill others by the so-called Lord’s Resistance Army. Faced with the opportunity to resist this horror with deadly force, he reluctantly accepted it and became the Lord’s Resistance Army’s worst nightmare. Because of his violent resistance to LRA numerous children’s lives were saved and many more were rescued from child soldierhood.
What advice would Niebuhr give to the Machine Gun Preacher? I think he would congratulate him for daring to get involved in a bloody, messy struggle to save children’s lives but warn him against over use of violence, against vengeance, and against ever believing his cause is wholly righteous and without sin. He would urge him to use only what deadly force was absolutely necessary to save the lives of innocent children and to never think of himself as innocent. He would advise him to seek God’s forgiveness for being involved in violence even though it was thrust upon him and he had little choice given the circumstances. He would remind him that this is a broken world and there is no perfection and violence is always a sign of that brokenness, even when it is necessary. He would tell him to “sin boldly and repent more boldly still.”
I agree with Niebuhr and Gutierrez that Christians, that I, must be open to the call of God to take up power, even deadly force if necessary, to defend the weak, the helpless and oppressed. With Niebuhr I agree that such use of coercive force for any cause is less than perfect, is even sinful, and never something to be celebrated or boasted of.
With great reluctance and admission that repentance is called for, were I in the Machine Gun Preacher’s shoes I hope I would have the courage to do the same as he. And I hope I would remember that even such a just cause is fraught with ambiguity and unrighteousness and requires grace, mercy and forgiveness.
There are times when we find ourselves caught in a situation where can have no choice but to sin because all the alternatives available are not what Christ commanded in the Sermon on the Mount.
Yes--a grave danger. Which is why I insisted that repentance is always the only proper response when we find that we must do what Jesus would not do or commanded us not to do. It's not license to do whatever we want to do.
To my way of thinking, shaped as it is by the Sermon on the Mount, even self-defense or other-defense using deadly force is evil. But sometimes it's necessary, justifiable and forgivable.
Yes, in my opinion (as I explained here some time ago in an essay entitled "Sin Boldly: Christian Ethics for a Broken World") some actions are neither ethically purely right or ethically purely wrong but simply necessary. In that case they are justified even if they violate law (God's or man's) and should be forgiven.
So Olson believes in moral dilemmas. Here's a philosophical definition:
The agent thus seems condemned to moral failure; no matter what she does, she will do something wrong (or fail to do something that she ought to do).
That's a logical consequence of his freewill theism. God can't guarantee that we will always be in a position where we have a morally licit option. That's because the choices of some free agents create the circumstances to which other free agents must respond. God can't control those circumstances because he can't control the choices which generate those circumstances.
That, however, creates an interesting parallel. A staple objection to Calvinism is that it's unjust, indeed "monstrously" unjust, for God to blame us if we could not have done otherwise.
Yet Olson thinks some Christians will find themselves in situations where they must commit blameworthy actions. Where it's necessary to do something sinful, culpable, evil.
Despite the fact that Christians have no sinless alternative in that situation, they should repent of their necessary action. They should seek divine forgiveness.
Of course, that only makes sense if their actions are blameworthy–despite the fact that they had no blameless options. They are required to sin, and they are required to repent of their sin.
Conversely, you have Calvinists like John Frame who deny moral dilemmas. For him, God has providentially prearranged events so that Christians always have a morally licit option. That stands in ironic contrast to Olson's freewill theism.