You do, I hope, realize that Ghavrel is a Christian, yes? Who would not exactly be inclined to approve of ludicrous suggestions that his faith is somehow inherently violent. I'm not a Christian myself, but I wouldn't approve of it either.
And as for "favoritism", did you even read the sentences in Ghavrel's earlier post that preceded the "when Christians look down their nose at Islam" one? Your hypothetical Muslim visitor could well take offense at that as much or more than at your statement mirroring Ghav's above. There is nobody in this thread who is guilty of the blatant favoritism that you complain about - plenty of them to be found in the wider world, I've no doubt, but then go complain to them there.
"Justify" is always a subjective concept, and again, Jeordam is right when he says that at the end of the day people are responsible for the actions they commit, whatever their justifications. All the same, it's important to take context and background into account, both for moral reasons - I think we can agree, in the abstract, that there are circumstances in which killing a man is less reprehensible than in others - and for the sake of determining what the best policies towards the group in question are.
In many, perhaps most cases, the justifications that terrorist use are particularly flimsy in the sense that they can't even claim to have suffered personally from the supposed evil that they are attacking. The 9/11 bombers are cases in point, as are those Chechens who committed the Boston bombing - "retaliating" for what happened in Chechnya, despite not having experienced it all first-hand. That is where the part about identifying and feeling connected to people in different times and places comes in, which is something we all do - partially as conscious choice, partially also inevitably through our upbringing and education.
Of course, most of us are not led to violent crime as a consequence of it. Most Muslims are not, either. Often you see a terrorist claiming to retaliate for something he didn't actually live through, while those who DID live through it don't commit such horrible acts and merely try to go on with their lives.
When a Muslim does something terrible today, it may well have a bearing on how you view or treat other Muslims. In a perfect world it shouldn't, indeed, but this is hardly a perfect world. And as for "justifying" retaliatory attacks, like I said, justifications are never objectively right or objectively wrong, but sure, it could do so to the same extent as the reverse would have done on the other side.
The main difference, and the reason no doubt for your claims of double standards, is that most denominations of Islam are in a serious crisis. There are so many different violent or less violent conflicts, essentially political but in which Islam is involved one way or another, that the context is simply so much more complicated than for your hypothetical Christian who feels inclined to retaliate for something horrible a Muslim terrorist has done.
You fail again to grasp the essential distinction between "Christian" and "Christianity", and more importantly in the context of the thread the analogous distinction between "Muslim" and "Islam". You dismissed my previous explanation out of hand further below, but perhaps you'll listen this time. When one makes statements about "Christianity" or "Islam", every single believer of those faiths will feel personally concerned - flattered or insulted as the case may be. But there is no single Christianity and no single Islam (except on the purely theological level where you can try to find points on which all believers of a faith agree). Even less so when you look at the history of a faith as well as its current incarnations, as you must. Which is where the part comes in about how Ghavrel and I disapprove of how Christians look down their nose at Islam, claiming that Christianity as a religion is superior to Islam as a religion. As opposed to looking down their nose at certain Muslims or groups of Muslims, which is very different, and which will also allow the Muslims who agree with them to say so.
Really? Can you show me the sentence where the initial argument lumped him, personally, in with them?
If you or Jeo want to claim that my point about identifying with people in other times and places does not apply to you, well, to be honest I strongly doubt I'll believe you, but go ahead. It would undermine the way I tried using Jeo's own words to illustrate a point, that's true, but not the point itself.
Edit to tone down the subject of my post.