The Icon of Kazan

 The Soviet regime was ostensibly committed to the complete annihilation of religious institutions and ideas. Militant atheism was central to the ideology of the Communist Party of the Soviet Union and a high priority of all Soviet leaders. Communism required the abolition of religion. Convinced atheists were considered to be more virtuous individuals than those of religious belief.
The state established atheism as the only scientific truth. Criticism of atheism or the state's anti-religious policies was forbidden and could lead to forced retirement, arrest and/or imprisonment.
The history of Christianity in theSociet Union was not limited to repression and secularization. Soviet policy toward religion was based on the ideology of Marxism-Leninism, which made atheism the official doctrine of the Soviet Union. Marxism-Leninism has consistently advocated the control, suppression, and, ultimately, the elimination of religious beliefs.
The state was committed to the destruction of religion, and to this effect it destroyed churches , mosques and temples, ridiculed, harassed and executed religious leaders, flooded the schools and media with atheistic propaganda, and generally promoted 'scientific atheism' as the truth that society should accept.

The Icon of Kazan, the most treasured Icon in Russia vanished during the Russian Revolution.

After the Russian Revolution of 1917, there was speculation that the original icon was in fact preserved in St. Petersburg. Reportedly, an icon of Our Lady of Kazan was used in processions around Leningrad fortifications during the Siege of Leningrad. There was a conflicting theory that the image had been sold by the Bolsheviks abroad. Although such theories were not accepted by the Russian Orthodox Church, a reputed original (one of several in existence) was acquired by the Blue Army of Our Lady of Fatima and enshrined in Fatima , Portugal in the 1970s.

In 1993, the icon from Fátima was given to Pope John Paul II, who took it to the Vatican and had it installed in his study, where he venerated it for eleven years. In his own words, "it has found a home with me and has accompanied my daily service to the Church with its motherly gaze." John Paul II wished to visit Moscow or Kazan to personally return the icon to the Russian Orthodox Church. The icon was presented to the Russian Church unconditionally in August 2004. On August 26, 2004 it was exhibited for veneration on the altar of St Peter's Basilica and then delivered to Moscow. On the next feast day of the holy icon, July 21, 2005, the icon of Kazan was placed in the Annunciation Cathedral of the Kazan Kremlin.