The problem is that Christianity, in the last analysis, is also foreign to the European soul. Yes, for centuries, Christianity was "Aryanized" and served as the basis for a Western civilization, but the underlying rot was always there, the positive driving force was always the natural European creative impulses grafted onto the foreign Christian creed. It served its purpose, but once the West moved from "culture" to "civilization" Christianity became worse than redundant: it became destructive. Note that during the Ottoman era Islam went into decline, but is now once again resurgent and militant, and this resurgence and vibrancy is due to the fact that Islam is well suited to the Arab soul, to the Iranian soul, etc. That's their natural religion and culture, so they embrace it with enthusiasm. Christianity, on the other hand, remains in terminal decline in the West, and is growing only among non-Whites: Latin America, certain areas of Asia (e.g., South Korea), and Africa. One cannot imagine a resurgent Christianity in Europe because it never really belonged there in the first place.
With Christianity exhausted, with "God is Dead" in the European heart, with Christianity now transformed into a political creed of politically correct Neo-Marxist ethnomasochistic self-abasement: Whites have no where else to turn. They have nothing. They are spiritually empty. So, some turn to the religions and civilizations of other peoples, alien as they may be, because at least those creeds exhibit: Strength! Traditional sex roles! Decisive action! Conquest! A Higher Objective! And what does the "Christian West" offer? Homosexual marriage? Feminism? Genocidal mass immigration? Tax cuts? Libertarianism? Hedonism? The Emperor has no clothes: the West is spiritually bankrupt, culturally defective, and deficient in honor, glory, and vision.