A Roman Catholic will probably feel very comfortable walking into an Orthodox Church. Services are led by clergymen, there are sacraments, many of the traditions and art are also similar, etc. But, Orthodoxy also has elements that will be unfamiliar—a married priesthood, communing infants, and so forth. 

Below are some questions and answers that address many of the most common issues that Roman Catholics may wonder about:

Do Orthodox Christians pray the Rosary?

Some people state that the Rosary dates from the 1400s, well after the split between Rome and the Orthodox Church, and that the use of the Rosary is unknown in Orthodoxy. However, the tradition of perpetual prayer precedes Christianity. Why would St. Paul have told the Thessalonians to have prayed "without ceasing?" (1 Thess 5:17)In Orthodoxy however, we have the Jesus Prayer (“Lord Jesus Christ, Son of God, have mercy on me a sinner”) with a knotted prayer rope (or sometimes with beads). Other brief prayers may also be associated with the use of the prayer rope, though there is not any corresponding system of imaginative systems of meditations as there sometimes is in Roman Catholicism. 

What about Purgatory?

Purgatory was developed in 12th century Roman Catholic theology to explain how the dead can work off the residual debt accrued from sin prior to the Second Coming. The teaching is that the slate needs to be clean before a person can come before the Judgement Seat, that “satisfaction” must be made either in this life or in the intermediary state of Purgatory before entering the Kingdom of Heaven. The Orthodox view of salvation is more process-oriented, and does not believe that sin and grace are quantifiable substances that must somehow be in balance before someone can enter God’s Kingdom. We also do not believe that “satisfaction” can be made for sins. God does not need to be satisfied but instead desires to heal us of our sins. A loving God who forgives and heals does not hold anything against us.

There is just sin, and although some are more serious than others, Orthodox do not make the distinction between mortal and venial sins that Roman Catholics do. Because sin causes us to deviate on our path to salvation, any sin is believed to be serious in Orthodoxy. We progress toward holiness (deification or theosis), and this is a process that will not be completed in this lifetime. Indeed, the work of holiness is an eternal one, since God’s holiness is limitless. 

Orthodox Christians and Roman Catholics both believe in the real presence of Christ in the Eucharist. Does Orthodoxy believe in transubstantiation?

Isn't it funny how a Greek philosopher is somehow responsible for the doctrine of transubstantiation? Transubstantiation is a Roman Catholic doctrine based on the teachings of Aristotelian philosophical categories. Basically, how can something change when it still looks the same?

We simply take our Lord's word for it. "Receive, eat, this is my Body!" and "Drink this all of you, this is my blood of the New Covenant!"

Orthodox Christians believe in the Real Presence and accept it as a mystery. Some things, if not most are beyond the use of reason.  As a consequence, we Orthodox are comfortable with accepting mysteries like the Real Presence as what they are—mysteries, without feeling obliged to explain them.

Why else would we approach the Body and Blood of Christ with "Fear of God, with Faith, and with Love?"

Can Roman Catholics receive communion at an Orthodox church?

Whoever wishes to receive the sacraments in the Orthodox Church must go through the process of joining the Orthodox Church, just as someone would do if they wanted to become a member of the Catholic Church. Fortunately, it's a wonderful process! 

Why do the Orthodox fast so much?

We don't fast all the time - just most of the time! This kind of practice really is part of Roman Catholic tradition, but it not practiced in many parts of the world. 

Fasting is one of many tools that we use to bring our bodies “under subjection” as St. Paul said (I Cor. 9:27), so that we might be pure and holy. Jesus said that when He had gone, His followers would fast. Like the early Christians, we fast so that we may learn to control our appetite for all things that are not good and holy. It is not about earning salvation, it is a tool to help us work out our salvation with fear and trembling (Phil. 2:12), enabling us to train and strengthen our wills so that they can prepare ourselves to encounter Christ.

Specifically, we fast each Wednesday to commemorate the day when Jesus was betrayed and each Friday to commemorate His death on the cross. In addition, we fast during the entire Lenten period and the entire Advent period, as well as during other times during the year.

Orthodox fasting practice, when followed strictly, means that the believer does not partake of any animal products from vertebrates (i.e., no meat, dairy, eggs, etc.), nor of olive oil nor wine. These choices reflect the desire to do no harm on these days, as well as giving up certain staples of life.

At the same time however, we should never approach fasting with a legalistic mentality. Fasting is for the health of the body and soul so that we can prepare for the salvation of the soul and body. If there are ever any questions about fasting, or if there are issues surrounding someone's health (i.e. if one is elderly, pregnant, or perhaps too young to fast) they should seek the council of the priest so that he may help you decide as to how to exercise discretion when fasting.

What is the Orthodox view of Original Sin?

Corruption and mortality are conditions of the world that we were born into because of Adam's disobedience. The focus in Orthodoxy is with the state of mankinds body and soul, as opposed to his legal status. The importance of this is how we relate to Jesus Christ. He is our Lord and Savior who defeated Sin and death through His own death. He's not a legal advocate because of our inherited guilt. He is perfect God and Man who heals us from our corruption and mortality.

Why don’t Orthodox believe in the Immaculate Conception?

Christ's perfect humanity is because He was also perfectly divine. Why would He need an immaculately conceived Mother? Mary (like all of us) was born mortal as a result of the Fall. But for Roman Catholics, a special conception for Mary was necessary so that Christ could be born to a spotless vessel—she was therefore declared in 1854 to have been conceived without “the stain of original sin.” So the Immaculate Conception is a natural consequence of the Augustinian doctrine of Original Sin in the West, but is not needed in Orthodoxy to explain how mortal Mary could have given birth to a perfect Son. 

At the same time, while both Roman Catholics and Orthodox Christians believe in the Virgin Mary’s great holiness, for Roman Catholics, this holiness is the result of the Immaculate Conception; that is, she could not have sinned. But for Orthodox Christians, her holiness is the result of struggle against the passions that beset all human beings after the Fall. The Orthodox belief in Mary as the first among Saints is far more profound in the sense that It is far significant to be holy when one doesn’t have to be.

What are the differences in the belief regarding the Assumption of Mary?

Roman Catholics believe that Mary, because she was born without the stain of Original Sin, did not have to die; as a consequence, she is the only human being to be assumed directly to heaven without passing through death. Of course if we read the scriptures, we know that this isn't true (both Enoch and Elijah were taken up into Heaven!)

On the other hand, if Mary having inherited Adam’s mortality like all other people, died. However, our Lord immediately raised her from the dead as one of the first fruits of his Redemption, and she was assumed into heaven. This is why the icon of the Virgin Mary’s death (her “Dormition”) shows her lying on her death bed, with her Son behind her holding a baby in swaddling clothes. The baby represents His mother’s soul whom he has raised to her life with Him in heaven. On August 15, the Orthodox celebrate Mary’s Dormition (“falling asleep”) rather than her Assumption.

Thus, both Roman Catholics and Orthodox Christians believe that the Virgin’s body is assumed into Heaven, but Orthodox Christians believe that the process included her death. A seed cannot blossom unless it is first planted into the ground.

What does Theotokos mean?

It means “Bearer of God,” but its literal sense is “birth-giver to God.” The title was given to Virgin Mary at the Third Ecumenical Council in Ephesus in 431. It affirmed that in the Incarnation God was truly born of a mortal woman. It is a Universal belief held by Catholics, Orthodox, Oriental Orthodox, and many Protestants as well!

Why are Orthodox priests allowed to marry?

Orthodox clergy—bishops, priests and deacons—are not allowed to marry after ordination, though married men can be ordained as deacons and priests. (Bishops are celibates and often monastics.) The decision to marry or not must be made prior to ordination, and in the event of the death of his wife, an ordained clergyman may not remarry unless he permanently leaves the diaconate or priesthood.

Orthodox have always insisted that celibacy had traditionally been optional for clergy since the first century, citing scriptural and other evidence for married priests and bishops (e.g., Mark 1:30, I Timothy 3:1-5). Also, the decisions of local councils are not binding on the Church as a whole; only the decisions of Ecumenical Councils are universally binding.

As is the case in the West, bishops have been celibate in Orthodoxy since the 5th century, a canon law instituted initially to halt the loss of land holdings to the descendents of married bishops. Note, too, that all monastics are celibate in the Orthodox Church. 

Both Orthodox Christians and Roman Catholics make the Sign of the Cross, but why is the order different (Orthodox start with their right shoulder, but Roman Catholics start with their left)?

The tradition of crossing one's self dates back at least to the 2nd century and is made by Christians throughout the entire world. There are a number of possibilities as to why this happened. But, no one knows exactly why. It’s worth noting that some of the other historical Eastern churches, such as the Copts and the Armenians, make the sign of the cross roughly similar to Roman Catholics.

Roman Catholics make the sign of the cross with the five fingers next to each other, to represent the five wounds of Christ (head, hand, hand, torso, feet). Orthodox make the sign of the cross with the thumb, index, and middle fingers together, representing the Trinity, and the fourth and fifth fingers pressed into the palm to represent the two natures of Christ.

Why are Orthodox children allowed to partake in Communion, but Catholic children have to wait until 1st or 2nd grade?

Roman Catholic doctrine holds that a child must be old enough intellectually to understand the mystery of Christ according to “his capacity.” He should be able to discern the difference between the Eucharist and ordinary bread. Western doctrine places a premium on the role of reason in understanding God and in forming a relationship with Him.

Orthodoxy, on the other hand, believes that God in His Essence is unknowable, and dwells in “divine darkness.” No one will ever apprehend the mysteries of God, the Incarnation, or the Eucharist through reason. Why, then, withhold the grace of the sacrament from those whose understanding is after all only a little less than an adult’s? As a consequence, Orthodox do not believe in holding back children (or those who who are developmentally challenged and may be permanently incapable of reason) from receiving the Body and Blood of Christ.

As with certain other practices, the delay of communion (and confirmation, as well) is something that developed gradually over time for Roman Catholics. Ancient Roman practice was nearly identical in this regard to Orthodoxy—baptism, confirmation (chrismation) and communion were all given to infants. This is still the practice of the Eastern Catholic churches, which resemble Orthodoxy in many ways but belong to Rome.

What is the difference between Roman Catholicism and Orthodoxy in canonizing saints?

For Rome, the declaration of a saint is a more-or-less top-down process; by recognition of miracles by the hierarchy, analysis of the prospective saint’s life under the direction of the hierarchy; and the juridical approach involving a “Devil’s Advocate.” For Orthodoxy, a saint is recognized as such by more of a bottom-up process: the community recognizes the saint’s holiness, which is then investigated, acknowledged and proclaimed by the hierarchy.

Why does the Orthodox Church use leavened bread and the Roman Catholic Church use unleavened bread (wafers)?

The differences between Orthodoxy and Roman Catholicism on the use of bread in the Eucharist arose because of differences in understanding of the nature of the Last Supper (as a fellowship meal per the Gospel of John in the Orthodoxy, as a Passover meal per the synoptic gospels in Roman Catholicism), and perhaps also of the theological symbolism of leaven. The Orthodox have generally maintained the symbolism of “risen bread to signify the risen Christ.” This difference was an issue of major controversy around the time of the Great Schism, though it is less discussed today.

Why do Orthodox Christians say that the Holy Spirit proceeds only from the Father, rather than from the Father and the Son?

The formulation in the Nicene-Constantinopolitan Creed, which represents the faith passed down from the Apostles, did not originally include “and the Son” (in Latin,filioque). It agrees with the theology of Scripture: the Gospel of John quotes Christ Himself in saying “But when the Comforter comes, whom I shall send to you from the Father, the Spirit of truth who proceeds from the Father, He will testify of Me.” (John 15:26). The filioque clause was introduced in the West at a local council in Toledo, Spain, in 589. Over the coming centuries, it would spread in the West as theology (under the influence of Charlemagne’s Frankish theologians) drifted from a common understanding with the East. In the year 1274, a council of the Roman Catholic Church in Lyons, France made the filioque an official part of the Nicene Creed in the West.

Besides its disagreement with the words of Christ and its contradiction with the original Creed, the filioque also results in a subordination of the Holy Spirit: If two Persons of the Trinity (the Father and Son) share on thing that the third Person (the Holy Spirit) lacks, then how can the Spirit truly be equal to the Father and Son? Orthodoxy sees rather a perfect balance in the Trinity: Anything that can be said of God is either equally applicable to all three Persons or uniquely applicable to only one Person.

How do Orthodox Christians view the authority of the Pope, and the Primacy of Peter?

The Patriarchate of Rome is one of the five historic patriarchates of the Church, the others being Constantinople, Alexandria, Antioch and Jerusalem. Orthodox accorded the Pope of Rome the respect due the “first among equals.” Even today there is an agreed primacy for the See of Rome. However, Orthodoxy holds that primacy was always understood as a primacy of honor and coordination rather than a primacy of sovereign authority. For the Orthodox, all bishops are fundamentally equal.

Roman Catholic theologians would counter that the understanding of the special status of papacy evolved over time in the West under the influence of the Holy Spirit; Orthodoxy would insist that the authority granted the first bishops, the apostles, was granted once and for all, and that the revelation of authority in them within the Body of Christ does not evolve over time.

Orthodoxy also believes that all Orthodox bishops are the successors of Peter and that Rome’s pope cannot hold this status uniquely.

Why aren't the Catholic and Orthodox Churches united?

Answers to questions like this are never easy - especially considering that many of us in America are products of what are considered to be "mixed" marriages (i.e. people of other faith traditions inter-marrying). Regardless of what our leaders do at the ecclesiastical level, Christians of every denomination should desire that all people be united to Jesus Christ. This is accomplished through through living a Christian life through prayer! It's our love of God and one another that will save us.