There were several differences resulting in the `'eastern schism`.
1) whether the Bishop of Rome is legitimately the `Pope' with authority over all Christendom (as believed by the Roman Church) or one of a group of important bishops (technically, the Pentarchy).
2) double vs. single procession of the holy ghost (the filioque)
3) the authority of the 7 ecumenical councils vs. those plus subsequent accretions
4) shape of tonsures
5) whether no priests can marry (Roman) or secular priests can marry but not monks or bishops (eastern)
6) whether the Host is leavened (eastern) or unleavened (Roman) bread
and a few other geographical, ritual, and theological controversies (e.g. whether the Virgin Mary can be called mother of God or only mother of the human nature of Jesus)
I must agree that, at the bottom of it all, they both follow the Christian faith. Outside of that, they differ in the same ways other Christian faiths do (for one example, there are differences in interpretations of their texts).
The differences are significant, but the commonalities are far greater. For example, they have the same Bible for the most part, the same tradition until the Great Schism, and they share many of the same creeds. If we look at something like the Apostle's Creed, then you will see that there is a lot in common. Things like architecture and liturgy are minor compared to the fundamental, where there is agreement.
When the first council of Nicea met in AD 325, there were divides created in the Christological issue of the relationship of Jesus to God the Father, the Nicene Creed, or profession of faith, the setting of the date of Easter, and declaration of canon law. These devides lead to the three-way split in the Catholic Church: Roman Catholic, Byzantine Catholic, and Eastern Orthodox. While Roman and Byzantine recognize the Pope as the jurisdictional head of Christendom, the Orthodox do not [Russian Orthodox, Greek Orthodox], nor do Protestants. Nevertheless, all of these are Christians who follow the Bible and the teachings of Jesus Christ. The distinctions are not in any essential Christian beliefs, but rather in the interpretation of fundamentals of the Christian faith and recognition of papal authority.
The differences are not as profound as those between Islam and Christianity, as both Orthodox Christianity and Western Christianity are based on the same theological premise, i.e. the resurrection of Christ as a redeemer. Another important point to make is that many of the divisions within western Christianity (i.e. between Catholics and Protestants) are perhaps more significant than the differences between Orthodox Christianity (which is itself not without divisions) and the west.
I would have to agree with those who claim that the differences are not as great as those between Christianity and Islam. After all, the latter differences have caused hugely violent and destructive conflicts throughout history (I am thinking particularly of the Crusades, as well as recent events). I'm not aware of conflict between the eastern and western branches of Christendom that has been nearly as extreme.
Honestly, I think it depends on whether you are on the outside or inside of the debate. If you do not belong to either group, you may not consider the differences significant. Matters of theology might not seem as crucial to you, and you might be looking at other factors.
I agree with post #3. There are significant differences in liturgy, in architecture of places of worship, and in viewpoints regarding specific interpretations of theological questions. However, Orthodox Christians and Christians of the western European churches are still all Christians, believing that Jesus is the Messiah, the Son of God.
Islam accepts Jesus as being a prophet but nothing more. That is a fundamental difference that can not be in any way compared to the differences between eastern and western Christian traditions.
No, they can't be seen as that different in my opinion. The main reason for this is that they are both Christian religions. There is not the same sense that one of them is completely wrong and therefore their practitioners do not see the other faith in such a negative light. They both see Jesus as a deity and both use more or less the same scripture. In addition, both come out of the same, mostly European civilization. So I don't think they can be as distinct as Islam and Christianity (especially since the Soviets didn't adhere to the faith and so it wasn't seen as a source of conflict like Islam is).
The differences are highly significant, especially when we consider theology, the form of the service and the role of the priest in these two different approaches to Christianity. I remember once going to an orthodox church in Serbia, and the differences just in terms of the layout of the church was incredible, especially when you began to analyse the murals and icons on the walls and how much of an integral part of orthodox worship they are.
All the Christian follow the same faith of Trinity essentially whereas Islam is a monotheist religion. There are differences in interpretations in Christianity and these differences are there in Islam too. The fact remains that after the 9/11 incident, Bush used the word 'Crusade' in his spontaneous speech, though other justifications for the usage of the words were given later. The west joined US in waging war against Muslims in Afghanistan without any proof as they did in the case of Iraq War on the false account of WMDs irrespective of their own sectoral faith difference of Christianity. So from the stand point of oneness against other faiths like Islam, Orthodox and Western Christianity is the same.