When looking at the map of Europe, it can be divided and identified in three groups of religious practices.
Northern Europe is predominantly Protestant (Northern Germany, Holland, United Kingdom, Scandinavia).
Eastern Europe is mainly Orthodox (Greece, Romania, Russia, Serbia, Ukraine)
The third group, predominantly Catholic, covers 23 European countries (Austria, Belgium, Croatia, Spain, France, Italy, Poland, Portugal, Slovenia)
A fourth group, although a minority, may be added. This is Islam, which is present in the Balkans (Albania, Bosnia-Herzegovina) and in Turkey.
However, Europe will be open to all thoughts and religions.
So, for example, the Hindus will be meditating in Sri Swaminarayan Hindu Mandir, in the heart of London, and the Buddhists in the Migyur Karma Ling in France.
For the monotheistic religions (Christianity, Islam and Judaism) and Orthodoxy, worship can be practiced virtually everywhere in Europe. Please refer to the tourist offices of the country you plan to visit.