I've been asked to comment on this post:
i) I think it's good to begin by bracketing the specific issue of the imprecatory Psalms and discussing general principles. The relevance of the imprecatory Psalms to Christians has its own theological and hermeneutical complications which can be a distraction. It isn't necessary to settle that question to address the issue more broadly.
Even if the Bible didn't contain imprecatory Psalms, the issue would still arise. It's possible and initially preferable to consider the question from the standpoint of general ethical and theological principles.
ii) One question is why do we pray for anything? Off-the-cuff, I'd say there are two basic reasons:
a) I pray for what I'm unable to do myself. I ask God because only God is in a position to bring it about.
b) Even though I can do it myself, and may end up doing it myself, I first pray to God to acknowledge his authority in my life. He has the prerogative to make the choice for me or to block my choice.
iii) In the case of ISIS, one potential reason for asking God to forcibly intervene is that that's not the sort of thing I can do myself. That's the kind of thing we normally pray for: things we are powerless to bring about on our own.
In that respect, ISIS is the kind of situation we normally pray about. We usually pray for divine intervention in cases like that.
Of course, there's still the question of what kind of divine intervention it is fitting to pray for.
iv) Another issue is whether I should do something I'd never ask God to do. Take a self-defense situation. Suppose I have the wherewithal to defend myself. Maybe a violent house-burglar breaks into my home and threatens my family. I have a gun and I shoot him.
Suppose, though, I don't have a gun. It's odd to contend that it's right for me to do what it's wrong for me to ask God to do. If it's right for me to harm the assailant, why is it wrong to ask God to harm the assailant? If it's right for me to disable the assailant, why is it wrong to pray that God do so in case I'm impotent to do so?
Or suppose, for the sake of argument, that the US would be justified in militarily intervening to destroy ISIS. If so, why would that be right, but it would be wrong to ask God to do the very same thing? Why is it right for me to do what is wrong for God to do? And if it's not wrong for God to do it, why is it wrong to ask God to do it?
From what I can tell, Wynne's position lacks moral consistency.
v) Another ambiguity which routinely crops up in these debates is the identity of the "enemy." Suppose we define an enemy as someone (or group) who harms me or intends to harm me if he gets the chance. He has the means, motive, and opportunity.
Now, I'm an American living on the mainland. At the moment, ISIS is not a direct threat to me. At the moment, ISIS is not a personal threat to my loved ones.
If I were to pray for their destruction, that's not because ISIS is dangerous or harmful to me, but because ISIS is harmful or dangerous to others.
It's like the difference between defending myself against a mugger and intervening to defend a little old lady who's accosted by a mugger. It's about concern for a second party.
To say we should love our enemies in this context misses the point, because the enemies in question are not my enemies. Rather, this is more about neighbor-love.
vi) Prayer is not a forced option. It's not as if we can only pray for one outcome. Nothing prevents me from praying thusly:
"Lord, I pray that you will convert the members of ISIS to Christianity–but if you don't, I pray that you will destroy them before they destroy more innocent men, women, and children."
We can pray for two different outcomes. We can prioritize the outcomes in our prayer. "Lord, do this–but if not, do that."
Some people have a simplistic view of prayer,
vii) However, let's be realistic: when, in the history of the world, has God converted an entire army–or even a vicious head-of-state? It never or nearly never ever happens. That's not God's modus operandi.
God sometimes converts unlikely individuals under extraordinary circumstances. Take the claim that some Muslims convert to Christian due to dreams or visions of Christ.
However, armies are collectives. ISIS is a collective. Although God sometimes converts a massive collective, that rarely if ever happens overnight. That takes generations.
viii) Incidentally, although it may sound counterintuitive to say so, cursing an unbeliever can be evangelistic. Some people will never come to Christ so long as things are going well for them. It takes a personal calamity to shake them out of their pride and complacency. In principle, you can pray that God make an unbeliever suffer, not because you bear him ill-will, but because he needs to be miserable before he will turn to God.
ix) Suppose that Wynne is right. Asking God to destroy militant Muslims is wrong. What if well-meaning Christians are mistaken when they ask God to do so?
Even if that's the case, what harm does it do? It's not as if we're forcing God's hand. God won't respond: "I was afraid you'd ask me that! I was hoping to avoid that, but I can't refuse your request. Against my will, against my better judgment, I'm bound to do as you ask. Your wish is my command."
Surely every Christian prays misguided prayers for time to time. Prayer is a paradox. We don't know ahead of time what to pray for. If we did, then in some cases that's not what we'd pray for in the first place.
Of course, you shouldn't intentionally pray for the wrong thing. And your prayer ought to be informed by sound theology.
But I think some theologians are too inhibited about the perceived risk of misguided prayer. The world won't come to an end.
x) Now let's briefly shift to the imprecatory Psalms. To begin with, I'm not clear on what it means to pray the imprecatory Psalms against ISIS. Does that mean reciting an imprecatory Psalm, but mentally redirecting it towards ISIS? Does that mean mentally or verbally substituting ISIS for the original referent?
xi) One of Wynne's problem is that he tries to ride two different horses. On the one hand he says these Psalms are timebound. They were tied to the unique cultic holiness of ancient Israel. That's past. That's unrepeatable.
On the other hand he says they're typological and eschatological. Future-oriented. But it's hard to see how they can be both.
xii) He relates the imprecatory Psalms to sacred space. But what in general do the imprecatory Psalms have to do with adversaries who defile sacred space? That's a very attenuated interpretation.
xiii) Let's also keep in mind that the Sermon on the Mount is set in the context of Roman subjugation. In that context, it would be futile at best and counterproductive at worst to violently resist political oppression. Self-defense would bring the full wrath of Rome's military machine down on the entire community.
xiv) Because Wynne thinks OT ethics has no direct bearing on this issue, he stretches Rom 13:4 to justify a war of intervention. But that has no contextual basis.