The parish is the basic organizational unit of the Catholic Church. It is where the people gather to pray and worship God, deepen their faith through Bible study and other faith-development programs, and grow as a community of believers. Vincentians sometimes staff parishes and sometimes offer Parish Missions—a ministry that finds its roots in St. Vincent himself.
Building or expanding a church is a huge expense. Building or expanding a school is as well. Developing programs to enlarge the ministerial gifts of the parishioners so they can serve their community well takes resources. When staffing a local parish, Vincentians often are faced with needs that exceed the resources of the local community.
Parish missions have Vincentians going, sometimes great distances, to preach a retreat to a parish. The goal is to deepen and enliven the faith of the people. Teams of Vincentians go to hear confessions, visit people in their homes, especially the ill and elderly and engage the youth. This is a service offered to parishes that are staffed by diocesan priests who themselves benefit from the visits of the Vincentian guests.