In 1949-09-08 Émilien made profession in the religious community of the Missionaries of the Sacred Heart (MSC: Missionaires du Sacré-Coeur). In 1955-06-24, he was ordained as a Roman Catholic priest in Rapide-Danseur. In September 1956, he left for the Dominican Republic where he taught at the Minor Seminary of the Missionaries of the Sacred Heart, worked for the Amigo del Hogar magazine, was named "superior" of the mission in the Dominican Republic, and in 1971 he became Administrative Provincial of the Missionaries of the Sacred Heart in that country.
Later, Father TARDIF founded the community of lay persons known as the Servants of the Living Christ (Serviteurs du Christ Vivant), which, in 1999, had more than 300 members. He opened several community homes in the Dominican Republic as well as in the state of Florida in the U.S.
In 1973, Father TARDIF returned to Canada because of failing health and was cared for at Laval Hospital in Québec City, QC. . While in hospital, he met members of the Charismatic Movement. Once cured of his health problems, he began preaching retreats throughout the world.
Father TARDIF's first book: Jésus a fait de moi un témoin, sold more than one million copies. It was translated into 18 languages. He wrote 2 more books before dying in 1999-06-08 while preaching a retreat to priests in Cordoba, ARGENTINA. His funeral was held in the stadium in San Domingo, Dominican Republic, and he is buried in Santiago de Los Caballeros, Dominican Republic.