The mission of the laity has been addressed with great care in the documents of Vatican II and specifically in the apostolic exhortation of John Paul II, Christofideles Laici (1988). “The laity is commissioned to seek the kingdom of God by engaging in temporal affairs [the affairs of this world] and ordering them according to the plan of God.” (CCC 898) “The initiative of lay Christians is necessary especially when the matter involves discovering or inventing the means for permeating social, political, and economic realities with the demands of Christian doctrine and life.” (CCC 899) Preparation for this mission comes through the foundational sacraments of baptism, confirmation and, for some, matrimony. The laity, given this comprehensive responsibility to help realize God's plan for the world, are depicted as the central and largest branch of the tree.

There are many branches of the laity entrusted with the task of bearing fruit - but only the two distinct lay vocations which are both discerned and chosen are depicted in the Vocation Tree: the married vocation, shown by the continuation of the broadest branch of the tree, and the dedicated single vocation.