Orthodox Christianity
The largest religious group in Russia and the western former Soviet republics are Orthodox Christians.
Christian
Russian people are the largest ethnic group in Russia.
Catholics
ethnic : Russia religious : Muslim
Shia
catholic
Islamic
The largest religious group in Afghanistan A+
Hi, Personaly I believe that Russia's major religious group is many actually Christianity, Islam,Buddism,and Judism. But to answer your question Christianity is the most studied religion in the Soviet Union (RUSSIA).
Roman Catholic
Chinese