During 1942–1944 he served as an assistant priest in his native Archdiocese. In 1944 he was transferred to Roman Catholic Diocese of Kamyanets-Podilskyi, when continued to serve as a parish priest and during a period of the Polish population transfers (1944–1946) he remained in the Soviet Union. Under the pressure of the Communist government he moved to Lviv in 1946, but two years later was again forced to leave Lviv and returned in the Diocese of Kamyanets-Podilskyi. Here he worked until 1991 under the Communist persecution of the religion. In the same time, he clandestinely joined the Congregation of Marian Fathers of the Immaculate Conception, were made a profession in 1988.