I'm not a member of Opus Dei, athough i support the traditionalist FSSP (Fraternal Society of St. Peter) which promotes the reestablishment of the Old Latin Mass and Breviary, its attributes and an undiluted Catechism.
I actually agree with you, but only to a point. The Rise and Collapse of Civilizations, as the West is, was well elucidated, especially by Oswald Spengler, in The Decline of the West, in the last century.
Many of his predictions, almost a century old, are being realized with uncanny accuracy now. Spengler was a dedicated Deist and (perhaps) a Gnostic as well, and was especially critical of the gospels of St. Paul, which defined Christianity's fundamental moral character, and his predictions thus contain an inherent bias.
But there has been an independent Christian strain to the progression of the West, interweaved and supportive through much of its history, but also in dissension with it when a strong Deist and relativistic character started to impose itself at the beginning of the Enlightenment.
That should indicate to you they have separate destinies. The West could well be on the road to ruin, led by a homosexual, hedonistic elite.. but Christianity will continue on.
I'm more like Spengler, Gnostic leanings and I think Paul was a mental deviant who completely messed up JC's message. As far as I'm concerned, the catholic church is the remnant of the old Roman Empire only two thousand years more decadent.
And yes, there are sufficient numbers of people who would rather be sheep than take responsibility for themselves so christianity will probably be around for quite some time to come.