Liturgy: The Second Vatican Council initiated great changes in the liturgy of the Latin Church. When Latin Catholics attend liturgy in the Eastern Church, they find the celebrations different from their own.
According to Vatican II, “All members of the Eastern Churches should be firmly convinced that they can and ought to always preserve their own legitimate liturgical rites and ways of life, and that changes are to be introduced only to forward they own organic development. They themselves are to carry out all these prescriptions with the greatest fidelity. They are to aim always at a more perfect knowledge and practice of their rites, and if they have fallen away due to circumstances of time or person, they are to strive to return to their ancestral tradition.” It is clear from the words of the council that the vision for the Eastern Churches is very different from that proposed for the West, and therefore the success or lack of success should be judged accordingly. As long as Christians have been able to build their own churches, the areas of the altar had been marked out as a special place; sometimes rails have been used, and sometimes steps. In Byzantine churches, a screen of icons marks off the altar. This screen developed over many hundreds of years from a simple open screen to a real wall of icons, with doors (also covered with icons) that permit the celebrants to process to and from the altar. To the Latin Catholic, it may seem that the Church is trying to hide the altar from the laity, but the idea that something sacred can be “hidden” behind an icon seems strange to Eastern Catholics. Icons are always the sign of presence. The icons on the icon-screen are the household of Heaven made up of Christ, the Mother of God, the Angels, and the Saints. Heaven is with us when we celebrate the liturgy and, in a mystical way, actually celebrates the liturgy with us. For Byzantine Catholics, with their long history of theology and devotion, the icon-screen represents a real celebration of the presence of God among us.
Law: The cannon law of the Eastern Churches, which was revised after the Second Vatican Council, is contained in the Code of Canons of the Eastern Churches, which was promulgated by Pope John Paul II on October 18, 1990, and took effect on October 1, 1991. In accordance with this universal legislation, each of the Eastern Catholic Churches can develop its own particular law. There are some aspects of the discipline of the Eastern Churches that are well known to Latin Catholics, for example, the different discipline in regard to clerical celibacy. More recently, the Existence of married clergy in the East has been used as an argument for making priestly celibacy optional in the West. Questions posed by the Latin Church about it’s own life and discipline can only be answered by that Church from within its own tradition. The fact that some priests are married and some not has ever been a question of debate in the East. As Pope Paul VI noted, “If the legislation of the Eastern Church is different in the matter of discipline with regard to clerical celibacy…this is due to the different historical background of that most noble part of the Church, a situation which the Holy Spirit has providentially and supernaturally influenced.” Vatican II, in this matter, stated, “While recommending ecclesiastical celibacy this sacred Council does not by any means aim at changing that contrary discipline which is lawfully practiced in the Eastern Churches. Rather the Council affectionately exhorts all those who have received the priesthood in the married state to preserve in their holy vocation and continue to devote their lives fully and generously to the flock entrusted to them.” The Eastern Churches have a deep reverence for the celibate state as lived by monks and nuns. The episcopate, the fullness of the priesthood, is only bestowed on celibate priests. The Second Vatican Council sought the restoration of the permanent diaconate. The deacon has always had a central role in the liturgical life of many Eastern Churches, but unfortunately under the influence of the Latin Church, the diaconate came to be seen as a step towards ordination to the priesthood. The permanent deacon, both in the West and the East, is ordained “not unto the priesthood, but unto the ministry.” Nevertheless, the deacon is seen as a member of the hierarchy and not a layman. In the Liturgy, the deacon is at the service of the bishop and through him the entire Church. The deacon also has a role in preaching. As the Code of Canons of the Eastern Churches states, “Bishops, priests and deacons, each according to the grade of his sacred order, have as their foremost duty the ministry of the Word of God”. Deacons, like priests of the Eastern Churches, may be either celibate or married men.