The popular missions preached by Vincent and his newly founded community were a formative experience. Catechesis, or basic Christian instruction, played a very significant role in the course of all the popular missions. In fact, late in his life, Vincent wrote to a Priest of the Mission: “I have been deeply saddened by the fact that, instead of giving the regular catechism instruction in the evening, you have given sermons during your mission. This should not be done: (1) because the person who preaches in the morning might have difficulty with that second sermon; (2) because the people have greater need of this catechetical instruction and derive greater profit from it; (3) because, in giving this catechetical instruction, it seems there is, in a certain sense, greater reason to honor the manner Our Lord Jesus Christ used to teach and to convert the world; (4) because it is our custom, and Our Lord has been pleased to bestow immense blessings on this exercise, which offers a greater means to practice humility.” Vincent insisted that there be two catechetical sessions each day during the missions, one around midday (“le petit catéchisme”) and another in the evening (“le grand catéchisme”).