Over the last forty years , there has been a rowing commitment of many religious women and men to issues related to peace and justice, integrity of creation, integral development, option for the poor, fight for social and economic rights of women and children, and so forth. The objective of this book is to offer, in the first park, a kind of historical and theological foundation of the social apostolate and social ministry of the religious, and, in the second part, relevant passages from the Bible, from the Fathers of the Church, and from more recent Church documents. The book's Appendix, then, is not just a body of separate additional material. It rather turns out to be the best documentary foundation of what precedes it. By reading the two documentary foundation of what precedes it. By reading two documents after having gone through the first and second part of the book, one cannot fail to understand the meaning of the religious' presence in the world in a better way.