Christian countries perished before. The Middle East has been under Muslim occupation for centuries and the Christian minorities there are in rapid decline; Byzantium is gone; North Africa has no Christians left; percentage of Russian Christians is in single digits twenty years after the destruction of the atheist Soviet state. The anti-religion, and especially anti-Christian sentiment is strong in Europe. We may perish too.
Christ spoke this of His return "the Son of man, when he cometh, shall he find, think you, faith on earth?" (Luke 18:8); this shows that the task of persevering His Church on earth He left to us, and we are not doing a very good job of it.