This article is a study of the compatibility of the theory and practice of Marxism-Leninism and Orthodox Christianity. The great importance of this topic is due to its direct connection with the improvement of society and the ongoing controversy on this issue with attempts to integrate communism with Christianity. The work provides a historical and theological analysis based on a critical study of the works of the founders of Marxism-Leninism, their associates, historical and theological works, as well as historical documents on this issue. The article examines the approaches of the teachings of Orthodox Christianity, as well as Marxism-Leninism to atheism, materialism, religion and the Church. For this purpose, the relevant texts of Holy Scripture, the opinions of the Church fathers and the views of the founders and followers of Marxism-Leninism are studied. The novelty of this study is that some documents are considered for the first time in the context of the problem under study. In addition, a more detailed and systematic historical and theological analysis of the comparison of the teachings of Marxism-Leninism and Orthodox Christianity on this topic is carried out in comparison with the available works. The purpose of the work is to study historical and theological works, as well as historical documents related to the problem under study. The article concludes that Marxism-Leninism in this matter is not compatible with Christianity and is directly opposed to it. Since the Second World War in the USSR, relations between the state and the Church have improved from time to time, but the official state course on Marxism-Leninism did not leave the possibility of their reconciliation. Currently, there are attempts to produce a symbiosis of these two teachings. Many Communists have a positive attitude towards the Church, so a dialogue between them is possible and necessary. But as long as the ideology of the Communists remains Marxism-Leninism, antagonistic to Christianity and any religion in general, in their ranks will always remain hostile to religion. Therefore, the synthesis of these teachings is impossible.