Pivarunas was born to Walter Pivarunas and to an ethnic
Italian mother on 31 October 1958 in
Chicago,
Illinois, United States. He was baptized on 7 December of the same year, in Seven Holy Founders Church in the same city. He received his first Communion on 7 May 1966, and was confirmed on 6 June 1967. Pivarunas entered the
religious life in the
sedevacantist Congregation of Mary Immaculate Queen (CMRI) in September 1974 at the age of 15. After a year's postulancy, he entered the
novitiate on 8 September 1975, taking the
religious name of Brother Mary Tarcisius. He made his first profession of
vows on 12 September 1976. On 12 September 1980, he made his final profession of vows. Since his episcopal consecration, Pivarunas has traveled to the United States, Mexico,
Canada, New Zealand,
South America, and
Europe to provide Confirmation and other sacraments to several thousand children and adults. According to the CMRI, there are over a hundred priests and religious under his spiritual care. ==References==