I say this not because I believe Christianity is a weapon in the present world struggle, but because I believe it is at the root of the struggle, not in terms of the physical organizations of Christianity versus those of atheism, but in terms of good versus evil, right versus wrong, in terms of "the stern encounter" of which Cardinal Newman so prophetically wrote:
"Then will come the stern encounter when two real and living principles, simple, entire, and consistent, one in the church and the other out of it, at length rush upon one another contending not for names and words or half views, but for elementary notions and distinctive moral characteristics."
Cardinal Newman spoke of this conflict as yet to come. Doubtless its climax is yet to come, but in essence the conflict has been going on for 2,000 years. It has not been limited to one nation or to one form of government. The issues, the slogans, the battlefields and the personalities have been different. But basically it has been the same encounter of opposing principles, a struggle more comprehensive, more deep rooted and even more violent than the political and military battles which go on today. It is easy to envision the struggle as being wholly physical – of men and arms – of stockpiles, strategic materials and nuclear weapons – of air bases and bombers, of industrial potential and military achievements. This is the material struggle, and the central problem here is to be equal to the sacrifices necessary for ultimate survival and victory. But of far deeper significance is "the stern encounter," the very nearly silent struggle, with no din to be heard in the streets of the world, and with weapons far more subtle and far more damaging than cannons and shells. The encounter of which I speak makes no more noise than do the inner process of disintegration.
Remarks of Senator John F. Kennedy at the Dedication Ceremony at Assumption College, Worcester, Massachusetts, November 10, 1956
https://www.jfklibrary.org/archives/other-resources/john-f-kennedy-speeches/worcester-ma-19561110