Rooted in the traditions of the earliest disciples, the Order (Rites) of Christian Initiation are the process of entering into the full communion of the Catholic Church.

The United States Conference of Catholic Bishops describes the Order of Christian Initiation for Adults as a process in which participants undergo “conversion as they study the Gospel, profess faith in Jesus and the Catholic Church, and receive the sacraments."  Rooted in the practices of the Early Church, OCIA is the normal manner of preparing adults for receiving the Sacraments of Initiation — Baptism, Eucharist, and Confirmation. Within the program, there are two groups: Catechumens, who preparing for Baptism; and Candidates, who are baptized persons seeking to complete their sacramental initiation through First Holy Communion and Confirmation.

The period consists of study, exploration, community-building, and faith formation, with liturgical rites interspersed throughout. Any and all adults or older children who have a desire to join the Church are invited into the ancient celebration of the Rite of Christian Initiation of Adults. During this process, participants are introduced to the beliefs, teachings, liturgy, prayer, and life of the Catholic Church.