This chapter highlights the most important characteristics of Russian religiosity and briefly describes the development of Russian religious thought from Russia’s adoption of Christianity in the tenth century up through the twentieth. It is emphasized that Russian religiosity strives to unite the divine and the earthly, in the interests of imparting to earthly reality a divine perfection. The author develops his view that Russian religious philosophy has always inclined towards the Gnostic version of Christianity, which denies the idea of the Fall and admits that the individual, as well as humanity as a whole, can achieve perfection in earthly life (i.e. the ‘Kingdom of God on Earth’ is possible). This point of view, first expressed by Pyotr Chaadaev, later became known as the concept of Godmanhood. Such a view lies at the centre of the philosophical outlook of the most famous Russian thinkers: Fyodor Dostoevsky, Leo Tolstoy, and Vladimir Solovyov. The author argues that the main trend of twentieth-century Russian philosophy was to prove the crucial importance of Christianity for the proper development of civilization, while Christianity itself was understood by Russian thinkers (Nicolas Berdyaev, Semyon Frank, Lev Karsavin, Andrei Tarkovsky and others) as a teaching not so much about God as about the divine nature of man.