After all the hard work and training, he was finally ordained as a priest in 1816
During his studies, Marcellin and a group of other seminarians discussed about forming a religious order under the patronage of Mary. This dream was realized in Our Lady of Fourviéres above Lyons the day after their ordination, then the group of young men together called themselves "The Society of Mary".
Marcellin was returning from visiting a sick person's home with a brother while a snowstorm was going on
After walking for about 2 hours, they both feel very weak. Marcellin said that they should pray that the Virgin Mary will come to their assistance.
The brother fell to the ground. Marcellin knelt down by him in the snow while reciting the Memorare prayer. Afterwards, he struggled to pick up the brother. Then, they both saw a light in the dark night. They followed the light, and they found a cabin which they spent the night in. They were safe at last.
On October 28, 1816 Marcellin was called to the house of a carpenter in Les Palais
16 year old Jean-Baptiste Montagne was dying while ignorant of faith. Marcellin instructed him, heard his confessions, then prepared him for death
After going to another sick person's home, Marcellin returned to the house that Jean-Baptiste was in. Marcellin found out that he passed away.
This event changed Marcellin. This event told him that he should evangelize to the young and or neglected people. As he was walking back to the parish house, he had a plan. He wanted to ask Jean-Marie Granjon to become the first member of his community of teaching Brothers.