How does one correctly transition from the New Rite Church to the Old Rite Church? What is the process, what should one know, and from which sins (such as smoking) should one abstain? #

The answer to this question largely depends on the individual’s specific life circumstances. It is one thing if the person is relatively healthy, young, and not in immediate danger of death, meaning they likely have time for a thorough preparation before joining. It is another matter entirely if the person is gravely ill, physically weak, elderly, or facing imminent danger, such as a risky surgery or military deployment, or another threat of death. In such cases, the process of joining should not be delayed for an extended period.

In the first case, where “time is not pressing,” it is recommended to undergo a period of catechesis before joining. During this period, one should study the faith, the history of the Church, strive to live according to Christ’s commandments, and renounce smoking, drunkenness, fornication, and other habitual mortal sins. One should also demonstrate a period of abstinence from such defilements to confirm genuine repentance and reform. This catechetical period may last 40 days (a traditional ancient practice) or even longer—several years if necessary—depending on the individual’s readiness. The duration is determined by the priest overseeing the person’s transition. St. Justin Martyr writes that during catechesis, the candidate must renounce pagan customs, especially offering sacrifices to idols; if they do not, baptism cannot be performed.

According to the Great Potrebnik, the catechumen is to meet with the priest weekly—specifically after Vespers on Thursday—to report on their spiritual progress and receive special prayers. Unfortunately, in modern practice, priests often do not require this of catechumens.

The rite of joining the Church varies depending on the person’s prior baptism and the community in which it was performed (if any). If someone was baptized in a heretical community of the 2nd or 3rd rank, where the baptism was performed by a heretical priest in the name of the Father, Son, and Holy Spirit with three full immersions in water, they are not re-immersed but are received through repentance and renunciation of heresy, followed by either chrismation (2nd rank) or purifying prayers (3rd rank).

If the person was not baptized with three full immersions in the name of the Father, Son, and Holy Spirit, or if they come from a heresy of the 1st rank, they are received through renunciation of heresy and full baptism.

In emergency cases, such as an imminent danger of death, the catechetical period is shortened to the utmost degree, and the person is received into the Church immediately following the catechesis. The priest has the authority to adjust the catechetical period according to the specific circumstances, always prioritizing the spiritual benefit of the person seeking to join the Church.

— Archpriest Vadim Korovin