In the not-too-distant past, adults who wanted to become Roman Catholics attended a few weeks of "convert instruction" and were quietly baptized in a private ceremony by the parish priest. It was a totally private process that involved only a priest and the inquirer. One of the great gifts of the Second Vatican Council in the 1960s was a renewed process of forming and initiating adults called the Rite of Christian Initiation of Adults (RCIA). In the words of author Thomas H. Morris, men and women involved in the RCIA today are "formed at the hands of the local community around the word of God, discerning and welcoming God’s invitation to embrace life in the Catholic Christian community, and thus serving the mission of Jesus in the world today."

The RCIA restores for the modern world the process the ancient Church used in initiating members. Early Christians realized that initiation is a process that proceeds through certain stages and that necessarily involves the entire faith community. At the Cathedral, inquirers meet weekly with a team of lay people and clergy who teach the faith, share their own experience of Christ in their lives, and accompany inquirers on their journey of faith. They also experience Scripture reflection on Sundays that opens them more fully to the powerful word of God.

RCIA is open to anyone, Christian or non-Christian, who genuinely seeks to explore the possibility of joining the Catholic Christian faith community.

Naturally, RCIA includes a substantial amount of instruction in the teachings of the Church. But first and foremost, RCIA is a process of conversion; it is about changing the heart and transforming the spirit. Along the way, inquirers participate in a number of ceremonies in which the Catholic community gradually affirms them for full membership. These ceremonies include the Rite of Acceptance/Welcoming, the Rite of Election, and the three Scrutinies (all described below). Initiation culminates at the Easter Vigil through the Sacraments of Baptism, Confirmation, and Eucharist administered by the Archbishop of Washington.

Catechumens are unbaptized persons who desire to be fully incorporated into the Catholic Church through the Sacraments of Initiation: Baptism, Confirmation and Holy Eucharist.

Candidates are those who have been baptized in the Christian faith and are seeking full communion in the Catholic Church through the Sacraments of Confirmation and Holy Eucharist. Proof of valid baptism in a recognized Christian denomination (by way of a certificate of baptism or letter of verification from one’s pastor or church of baptism) is required of all candidates.

Each catechumen and candidate is assigned a sponsor. The sponsor must be a practicing Catholic in good standing with the Church. It is recommended but not necessary for a sponsor to be a parishioner of the Cathedral. Catechumens and candidates may request that a Catholic friend or co-worker be assigned as their sponsor, but it is preferred that spouses and close relatives not serve as sponsors.

During the course of the year, the sponsor studies and prays with the catechumen or candidate and guides him or her on the journey of faith. The sponsors take an active role in the spiritual life of their catechumen or candidate and are vital to RCIA. They are selected early in the program and attend the Wednesday meetings and the ceremonies in which they play a role, and are expected to be present at Sunday Mass with their catechumen or candidate.

Catechumens will also need to choose a godparent or godparents for baptism. Godparents must be fully initiated adult Catholics who will be good role models.