Following the October Revolution of 1917, the Bolshevik seizure of power led to the Russian Civil War which continued until 1922. The victory of the Bolshevik Red Army enabled them to set up the Union of Soviet Socialist Republics (USSR). Throughout the civil war various religions, secularists and anti-clericalists of the Bolsheviks played a key role in the military and social struggles which occurred during the war.
Religious situation before the October Revolution
Since 1721 the Russian Orthodox Church (ROC) had been the established church of the Russian Empire. The church reforms introduced by Peter I introduced a period of Caesaropapism to the ROC. This meant that while the ROC enjoyed substantial privileges, it was nevertheless subordinated to the state. As the intelligentsia became more critical of the Tsarist regime, this was often accompanied by a rejection of the ROC, and sometimes by a rejection of religion in general. Others, such as Leo Tolstoy retained a strong Christian belief but rejected the autocracy. He was excommunicated by the ROC. Some Bolsheviks, such as Vladimir Bonch-Bruyevich became involved with the religious minorities collectively called the "sectarians". Bonch-Bruyevich joined Tolstoy and Vladimir Chertkov in supporting the Dukhobors, even sailing with a group of them when they migrated to Canada. In 1914 there were 55,173 Russian Orthodox churches and 29,593 chapels, 112,629 priests and deacons, 550 monasteries and 475 convents with a total of 95,259 monks and nuns in Russia.
Following the Bolshevik seizure of power
Eleven days following the storming of the Winter Palace a council of the Russian Orthodox church reestablished the patriarchate (it had been abolished under Peter the Great in 1721) and elected Metropolitan Tikhon of Moscow (Vassily I. Bellavin) as patriarch. Tikhon refused to take sides in the civil war, although the official Bolshevik propaganda presented him, as well as the Church, as supporting the whites. The Bolsheviks used the alleged support of the Russian Orthodox Church for the Whites as their justification for killing clergy in massive numbers. Following the Bolshevik seizure of power, one issue they faced was the removal of the privileged position of the ROC. The Declaration of the Rights of the Peoples of Russia (November 2/15, 1917) removed special privileges based on faith or nationality. This was soon followed by a decision by Sovnarkom to confiscate all the ROC's monasteries and educational establishments. When the Bolsheviks seized the Holy Synod's printing house, relations between them and the ROC became further strained. One issue was removing Orthodox Christian symbolism from state buildings. However, the Bolsheviks did not prioritise anti-religious campaigning, because they were concerned about how this would affect the popularity of the new regime.
Persecution of the Church during the Civil War
During the Russian Civil War, the Red Army massacred large numbers of clergy and believers often on grounds of alleged support for the Whites; much of these killings were not officially instigated from the top, but were done on the initiative of local units of soldiers. In later years, the church would declare that the excommunication was a misunderstanding based on the belief that these killings were officially instigated (however, they were never officially repudiated either). However, later Soviet authors would claim central responsibility for these actions, including Yemelyan Yaroslavsky (who was a participant in these killings) who justified the campaign by claiming that the church was fighting against them.
Many monasteries were attacked. Holy Mountain Monastery near Kharkov was plundered very early in the civil war. In a nearby skete in the village of Gorokhova a monk named Izrail was murdered for refusing to hand over the keys to the skete cellars. In the same area, a religious procession was attacked on its way as it rested the night, and two priests, a deacon, the owner of the cottage where they were staying at as well as his daughter were all killed.
Metropolitan Vladimir (Bogoyavlensky) of Kiev was the first bishop killed by the Bolsheviks on January 25, 1918. He had consistently opposed the revolution, and he was severely beaten as well as tortured before being shot outside the Monastery of the Caves. Before being shot by his murderers he prayed to God for them to be forgiven.