Western Europe has been predominately Christian since even before the Roman Empire adopted the religion. In 1054, the first separation of Christianity occurred when the Greek Orthodox Church split from the Latin Roman Catholic Church (Orthodoxy and Catholicism), this being the East-West Schism. Then in the 16th century, another separation of Christianity took place when several Europeans (mainly in Northern Europe) protested the Catholic Church and adopted their own form of Christianity, becoming known as Protestantism. Protestantism is formed of many different religions such as Anglicanism, Calvinism, Lutheranism, etc. This means that today, Christianity is split into three main branches: Catholicism (which remains the single largest denomination), Orthodoxy (composed of many different churches such as Greek Orthodoxy, Russian Orthodoxy, Romanian Orthodoxy, etc.), and Protestantism (which is the smallest of the branches).
The largest religion in Western Europe is Catholicism, which is the largest branch of Christianity. However, the fastest growing "religion" in Western Europe is no religion, as more and more Europeans in general are becoming unaffiliated or recognized Atheists.
The most widespread religion is Christianity.
Western Europe is mostly Catholic while Russia is Orthodox.
Christianity
Christianity
Christianity is the largest religion; Catholicism the largest subdivision.
Christianity
Yes there are Muslims all over the world, but there are a good number of Muslims in Western Europe, but it is not a major religion.
Southwestern Europe is predominately Catholic. In fact, Southwestern Europe is over 90% Catholic.
Some differences between Russia and Western Europe are that Russia is more Orthodox Christian and western Europe is more into Catholic religion. Russia has communism, but western Europe has democratic government. Other differences are that Russia has a strong military and loads of military weapons, but western Europe has none or less.
Western Europe is majority Catholic whiel Russia is majority Eastern Orthodox. Both are branches of Christianity, however.
Christianity, more specifically Catholicism.