He lost his parents at a very young age. In 1930, he was accepted into the seminary of the Diocese of Esztergom. He was sent to Argentina to continue his studies and to serve as a pastor to Hungarian immigrants. He arrived in Buenos Aires on August 24, 1936, completed his studies at the Villa Devoto Metropolitan Seminary, and was ordained a priest on September 18, 1937. He took up his ministry in the Diocese of Mendoza. He established a medical clinic and distributed food to the needy. Using donations, he founded the Virgen del Ville Chapel. The Colegio Padre José Müller school is named after him. He is revered as one of Argentina’s most significant catechists. He died tragically and suddenly; his estate was auctioned off, and the proceeds were sent to his impoverished relatives living in Hungary. His obituary noted: “As a Hungarian, he helped many Hungarians.”