The Vincentian Encyclopedia has posted an English translation of  THE FAITH OF VINCENT DE PAUL IN THE MIDST OF AN UNBELIEVING SOCIETY by Luis González-Carvajal Santabárbara.

“We have seen that even though Vincent lived in the midst of a situation seemingly different from our own, he did not find it easy to believe. His experience teaches us that the difficulties of life can become an authentic moment of kairos for the faith because, as mature love is that love which has overcome deception, so too mature faith is always faith that conquers the world (1 John 5:4).

 http://famvin.org/wiki/The_Faith_of_Vincent_de_Paul_in_the_Midst_of…

This article appeared in a Spanish language book of essays honoring the 350th anniversary.