Eastern Ukraine
According to a 2016 survey of religion in Ukraine held by the Razumkov Center, 73.5% of the population in Eastern Ukraine were Christians (63.2% Eastern Orthodox, 8.1% simply Christians, 1.0% Protestants, and 0.3% Latin Rite Catholics), 0.5% were Muslims, 0.3% were Jewish, and 0.3% were Hindus. Not religious and other believers not identifying with any of the listed major religious institutions constituted about 24.7% of the population. It also showed that approximately 55.6% of the population of eastern Ukraine (which in Razumkov's mapping excluded Donbass and consisted of the regions immediately to the west of it) declared to be believers, while 13.4% declared to be undecided or non-believers, and 3.5% declared to be atheist. 
A 2007 survey by the Razumkov Centre asked "Would you like to have your region separated from Ukraine and joined another state?" In eastern Ukraine, 77.9% of respondents disagreed, 10.4% agreed, and the rest were undecided. 
In a poll conducted by the Kyiv International Institute of Sociology in the first half of February 2014, 25.8% of those polled in East Ukraine believed "Ukraine and Russia must unite into a single state", nationwide this percentage was 12.5%.
Ukrainian Orthodox Church (Moscow Patriarchate)
The Ukrainian Orthodox Church (UOC; ; ), commonly referred to as the Ukrainian Orthodox Church of the Moscow Patriarchate (UOC-MP, ) is a member of the Eastern Orthodox communion. It is one of two major Eastern Orthodox ecclesiastical bodies in modern Ukraine. It is a constituent part of the Russian Orthodox Church (ROC); however, the Ecumenical Patriarchate, the senior-most of all the Orthodox Churches and the mother church for the historical Russian Church, disputes the legality of the ROC's ecclesiastical jurisdiction over Ukraine, which in the modern era dates back to 1686. The current statutes of the ROC define it as a "self-governing [church] with the rights of wide autonomy". the status of the UOC-MP within the Moscow Patriarchate meant that it enjoyed full administrative independence from the ROC's Holy Synod, whereas the Primate of the UOC-MP was the most senior permanent member of the ROC's Holy Synod and thus had a say in its decision-making in respect of the rest of the ROC, including its administration in the Russian Federation.