Your Question: What are the main differences between Orthodox and Roman Catholics, besides the Greek origin?

There are a few main distinctions between Roman Catholics and those whom we call “Eastern Orthodox.” The issues are varied and many, but I'll address here some of the major ones: the differences in origin, the role of the Pope, the Creed, and worship.

You are right that there is a difference in their origin. Early on, cultural differences between western Christians (those who spoke Latin and congregated around Rome) and eastern Christians (those who spoke Greek and congregated around Constantinople, among other places) created a difference in some of the practices and theology of Christians in the east and west. Eventually, some of these differences actually caused a division between Christians in the west, and most of those in the east.

There were several main reasons for the division. One is that western Christians look to the Pope as the vicar of Christ, and are therefore “in communion” with him. Eastern Orthodox Christians recognize the Pope as a “patriarch,” but they don’t see him as the head. Rather, Eastern Orthodox Christians are organized around several “patriarchates,” all of whom have authority and headship. There is special reverence given to the patriarch in Constantinople, but all of them operate somewhat independently and with their own authority. If we operated that way in Roman Catholicism, the U.S. Catholic bishops, for example, would not be bound to take direction from the Pope in Rome, but would have their own autonomy in a certain sense. As we have it, however, all Catholic bishops around the world are in communion with and are obedient to the Pope as the vicar of Christ.

A second major difference is not usually thought about a great deal among common Roman Catholics. Another major division occurred between Christians in the East and West over the Creed that we recite at Mass each weekend- the Nicene Creed. This is known as the controversy over the "filioque." In the Creed, we state that the Holy Spirit proceeds “from the Father and the Son.” The “and the Son” is “filioque.” This phrase was not a part of the original Greek text of the Creed when it was first written in the 4th century. It was added in the 5th century to emphasize Christ’s divinity when many people in the Church were denying that Christ was divine. The conflict is that the eastern Christians didn’t think the bishops had the authority to make such an addition, and that the additional actually changed the meaning of the Creed. The western folks saw it as simply making more explicit something that was already believed. Both sides got angry and division ensued. We often don’t realize how much work, sweat, tears, and passion had to happen to articulate the Creed that we say every weekend together. Those Christians went through a lot in order to come up with a way to clearly express their belief and preserve it throughout history in our beautiful creeds.

Another point of distinction between the Roman Catholics and Orthodox is our way of worship. First of all, there are a lot of similarities. We both believe in the “Real Presence” (though Eastern Orthodox wouldn’t necessarily call it that.) We both have a set form of worship every week (liturgy), and a similar church calendar. We also both honor the saints in the same way, and share many other practices as well. We both have religious brothers and sisters, as well as ordained deacons, priests, and bishops.

There are, however, differences. One difference between Roman Catholic and Orthodox worship, however, is in language. Our liturgy often comes from Latin. Theirs is Greek. This is a tricky point, however, because there are Eastern Catholic churches that have a litury that is Greek in origin, and that are actually Catholic and not Orthodox. This would mean that their liturgy looks almost exactly like that of an Eastern Orthodox church. The only difference is that the Eastern Catholic churches are in communion with the Pope in Rome, rather than the Eastern Orthodox patriarch. It can be very confusing!!! The bottom line, however, is that if you went into an Orthodox church and were accustomed to the Mass we have here at Three Holy Women, you wouldn't necessarily know what to do, though you'd recognize some of the same major elements.

Overall, we are very similar to our Eastern Orthodox brothers and sisters, and many efforts are being made to bring this great division between east and west back into communion with one another.