Most serious Christians are what Luther said: simul peccator et justus, at once sinners and justified. I know I am. Luther's error was to hold, in effect, that that's the best we can hope for. By contrast, the more ancient traditions of both Catholicism and Orthodoxy maintain that we can and ought to be truly and progressively sanctified, with our free cooperation, by that grace which is nothing other than the Trinity's self-communication to us. But Luther's point helps to remind us that, once we are beyond childhood, our chief enemy in the spiritual life is ourselves. Our external enemies, chiefly Satan and his minions, have only as much power over our souls as we choose, consciously or no, to give them. The same goes, I believe, for what's left of Christian civilization today.
Pace the callow evasions of our political and academic élites, our chief external enemy today is militant Islam, which is committed to our destruction as a civilization and has openly said so. I shall not debate whether, in the final analysis, Islam can be anything other than that. I think it undeniable that it is not. For one thing, whether the means employed are violent or not, Muslims as such are committed to the "struggle" (jihad) to win the world for Islam. That follows from Islam's being an essentially missionary religion. But the same could be said of Christianity, which is also a missionary religion; hence militancy, in the sense operative in the phrase 'the Church Militant', is not what distinguishes Islam from Christianity. The distinguishing feature of Islamic militancy is that it seeks to make Islam, precisely as such, the explicit basis of political authority wherever it is the dominant religion. For a long time, to be sure, Christians were wont to do the same with regard to their own religion; but save in a few isolated pockets, that approach has been given up, as it should be if Christianity is true. We've learned our lesson. Yet the Muslim world, the Umma, has not learned the lesson. Nor do I think it can. That is the main, underlying reason why the Umma has such a hard time repudiating al-Qaeda and other terrorist groups, such as Hezbollah and Hamas. It is the main reason why "Islamic" parties are gaining ground even in ostensibly secular states such as Turkey and Indonesia. All over the Muslim world, we hear more and more calls for imposing sharia, even on non-Muslims when possible. Even now, Christians in Iraq are reduced to the options of oppression or flight; Sunnis and Shi'ites, who seem to agree on little else and continue fighting each other, seem to agree on that much. That's the attitude which is steadily gaining the upper hand throughout the Umma.
Such a totalitarian and ineradicable feature of Islamic militancy is the polar opposite of the ideology that now dominates the Western world: secularism. The core principle of secularism is not the separation of church and state as institutions; most of us believers in the West agree that such separation is good for both. I for one am glad that the papacy no longer has temporal authority and that I live in a country whose constitution ensures religious freedom. For when religion is not adopted freely, according to individual conscience, it is to that extent an obstacle to human flourishing; and that's why people brought up in any given religion ought to think critically about it if and when they can, so that they can make their choice in an informed and adult way, consistently with their God-given dignity. But I object profoundly to secularism. For the core principle of secularism as an ideology is what I call autonomism: the proposition that man himself can and ought to define the basis of the state's legitimacy, without any necessary basis in or reference to a moral law higher than himself. From that standpoint, appealing to any "higher law"—such as what the Declaration of Independence terms "the laws of nature and of nature's God"—as the basis of the state's legitimacy is an unacceptable infringement on freedom of thought and conscience. Of course it is rarely explained why we should consider that moral judgment binding if we happen to disagree with it; the few explanations I've seen are patently inadequate even on their own terms; for they can be and have been used to justify the worst sort of tyranny—always, of course, in the name of "the majority," or the Volk, or the oppressed, or something like that. Secularism is worthless as a political ideology because its autonomism reduces in turn to moral relativism, which can justify anything and therefore nothing. We cannot truly secure the dignity and freedom of the individual unless we acknowledge the Authority, the "Higher Power," that they come from, and why we have no right to defy that Authority.
Indeed, relativism is why the secular liberals of the West, especially in Europe, have such difficulty coming to grips with the challenge posed by militant Islam. As relativists they are reflex multiculturalists; as such, they instinctively believe that if we would just be nice to the Umma, giving ground and money here and there while fighting only the most violent of the terrorists, then the threat would gradually fizzle and we could all resume enjoying our comforts and gadgets. Such an illusion, if indulged long enough by enough people, is fatal. It undermines the will to resist, and that's just what our militant Muslim enemies are counting on. They are right to hate secularism—and right to believe that Islam is stronger than secularism. The former has a spiritual energy and motivating force that the latter cannot sustain. Resurgent, militant Islam is indeed the just scourge of the secular West.
Our primary enemy, therefore, is within: our desire to set things up for ourselves independently of that God who can be known in the natural light of human reason. That is true on an individual level; that's why we're sinners, to the extent we are, and we all are. On the collective level, it is that God, and only that God, who must be acknowledged as the basis of the state's legitimacy. Although the God of divine revelation is infinitely bigger than that, he at least that—and only respect for the laws of that God, the God of "ethical monotheism," suffices to preclude tyranny. But secularism won't even allow us that much of a foundation. Only if we defeat that enemy within can we find the will to resist our chief external enemy, our just scourge, for the right reasons.