Born on July 2, 1876, in Kaysersberg (Upper Rhin), the youngest of four children of a Catholic family of modest means, Joseph Staub spends his childhood in Alsace-Lorraine, which was at the time part of the German empire. In November 1890 he enters the juniorate of the Assumptionists in Mauville, France. On September 8, 1896, at the noviciate of Livry, he receives the habit of the order and his new name, Marie-Clément. He stays in Livry until 1898 and, on September 8 of that year, takes his perpetual vows. At the end of his studies, which he pursues in Louvain and in Rome, he is awarded two doctorates – one in Philosophy and one in Theology – and is ordained priest on March 19, 1904. From 1904 to 1906 he is sub-prior of the noviciate in Louvain, then master of novices in Gempe. At the end of 1908 he is chosen to found the first Assumptionist juniorate in England.
The encounter with Edith Royer, a mystic who had had a vision of the Sacred Heart, convinces him of the importance of this devotion. He therefore works to propagate the teachings of the Archiconfrérie de Prière et de Pénitence, a confraternity devoted to the Sacred Heart. In 1909 he is asked to leave for America to preach and spread the ideas of the confraternity. He settles at the Assumption College in Worcester, Massachusetts. There, through the Sisters of Charity of Montreal (Grey nuns) who run the orphanage of St. Ann where he ministers, he is able to publicize the work of the confraternity in the province of Quebec too.
In 1914 he founds a religious community devoted to the service of priests and dedicated to Joan of Arc and the Sacred Heart. In 1917 Father Marie-Clément asks the Bishop for permission to establish, in the archdiocese of Quebec, the sisters of Joan of Arc, the Assumptionists and the Archiconfrérie de Prière et de Pénitence. They are accepted and establish finally in Quebec city in 1921. Father Marie-Clément dies on May 16, 1936.