The topic of this paper is Ivo Mašina's national and religious beliefs. The author first describes the life and work of Ivo Mašina and then explains the political and social context in which Mašina operated. The communist's government had initiated legal proceedings against him because of his catholic and patriotic views, which did not agree with Marxist ideology. The prosecutions and trials are described in detail. The center of the work is dedicated to the Mašina's national and religious views. These beliefs are based on the Mašina's historical profession and his religious life, which was consistent with the church's view of his own role in politics and society. Therefore, the paper analyzes the concepts of state, nation, nationalism from a historical and religious perspective. The doctrine of the church is presented through the documents of the magisterium, and there flection of Zagreb's Archbishop Alojzije Stepinac on the relationship between nationalism and Christian love for man. The analysis of the national, religious and social activities of Ivo Mašina is based on the historical understanding, the doctrine of the Church and the context of the time. The end of the paper deals with the description of Ivo Mašina's death and inheritance.