What the difference is between Eastern and Western Christians?
From thumbing through the Core 8 IG, my understanding is that Christians split into 2 groups some time about 1054 A.D.... with one group being Catholic (which spread to the west, and from which our western denominations have all come) and the other group being Orthodox (which spread east). Is that correct?
Yup, that's the way that I would sum it all up. Both groups were from the same origins, but had some slight issues of disagreement that caused them to split and go different directions (like Lot and Abram). That was one of the interesting aspects of studying this Core program....realizing that these church groups originated from the same foundations. And something that even the Core studies did not bring out significantly was that during the Crusades, the crusaders were actually killing other Christians (those of the Orthodox church) and Jews, along with the Muslims...often because they all looked very similar, but also because they were different than the European Christians. To this day, the term "Crusade" is a very negative word amongst the Jews and the Orthodox church. The book, The Ramsay Scallop, eludes to the awful nature of the crusaders' actions, but does not specifically address this.
To answer your question about the difference between Eastern and Western Christians "in a nutshell": It is my understanding that Christians were not divided into various groups prior to 1054. At that time some slight issues of disagreement caused them to split and go different directions. The Catholic church had its headquarters in Rome, and spread to the West. (And then, of course, over the years, split off into the various denominations we have now.) The Orthodox church's headquarters were in Constantinople, and they spread to the East. The reason most of us (in the West) have never heard of the Church of the East, is that apparently, the authors of our history books permitted political leaders of the Roman Empire to cloud their vision and convince them that the Roman Empire dominated the whole world, and outside the empire there was nothing of importance to record. There is, of course, a lot more to it than this, but hopefully this brief explanation will help.
History:We had a call from a client concerning the history of the charismatic movement -- was it even mentioned and what type of "light" was it mentioned in. It is not mentioned in every book and not often (once we hit the 1900’s), but it was always mentioned in a positive light. Also, assure her the IG is very strong on "unity" of the body of Christ.