What is western Europe's religion?

Answer 1

For many years it had been Christianity, but for the last many years, the majority possess Agnostic views and believe largely in Secular Humanism. To call Western Europe in general "Christian" is a falsehood. There may still be a connection to a "Christian" past and some state churches remain subsidized by the state, their teachings are largely secular and no longer based on Scripture and Christian faith. There are some free confessional churches which survive without subsidy, but they are by far the minority.

Answer 2

Western Europe does not have a central religion. But, the largest religion in that region would be Christianity.