Responsible citizenship is a virtue. The family, in turn, is the basic unit of society. As leaders of their family—which the Second Vatican Council called a "domestic church" Lumen Gentium , no. These truths about marriageare present in the order ofnature and can be perceived by the light of human reason. There, with the help of other couples and their pastors and collaborators, they can strengthen their commitment and sustain their sacrament over a lifetime. There is to be no separation between one's faith and life in either public or private realms.