It is not enough to assemble a lot of people in the church, one must instruct them, one must move them in a manner that they will be converted.
Letter to Jean-Baptiste Honorat, 27 January 1824 in O.W. VI n. 127
Whereas the morning instructions were catechetical, the evening instructions, referred to as “sermons,” aimed at the heart and at conversion. A perusal of the Diary of the Marignane Mission gives an indication of some of the topics that they dealt with in the evenings: what happens after death judgment, death of the just person as opposed to the death of the sinner, salvation, sin (introducing the theme of confession and inviting them to it), the dangers of delaying one’s conversion, the virtue of penance, the Prodigal Son, the Passion, forgiving one’s enemies, restitution, blasphemy, adoration of the Blessed Sacrament, the divine nature of the Christian religion, and many others.
Conversion, however, had to be built on the instruction they received:
I recommend you to aim very much at instructing. Be not satisfied with devoting the morning to this great duty of the mission, but always use a quick quarter of an hour in the evening before the main instruction to summarize what had been said in the morning to a smaller audience. This quarter of an hour instruction is to be given in the form of a reflection or catechism, without any oratorical gesture.
Letter to Hippolyte Courtès, 19 January 1839, O.W. IX n.683).