Aren't we supposed to be unified in our belief in the truth? Is it a divisive ploy from the enemy of our souls? Did God desire it to be this way?
I agree on the OP. But your OP is a little dangerous in that people post things and maybe don't realize the full ramifications of things.
A lot of it has to do with things like the verse
Amos 3:3
King James Version
3 Can two walk together, except they be agreed?
The problem is different people have different ideas of what proper Christian doctrine is and what a given interpretation of the Bible on a passage or number of passages is.
On the personal side, when I find a Protestant who is a "Bible believer" but also very derogatory against traditional Church teaching I always have this kind of issue in the back of my mind. Because many people don't realize how subjective Bible interpretation really can be (in fact this argument came up with last week with such a person). Anyway while the older Apostolic Churches are divided based on issues especially relating to a precise view of Christology they generally agree on a great large body of things, basically the main body of teaching outside of things like the nature of the Pope. And if you look at scripture, like saint Paul talking about "the milk of the word" as opposed to "the meat" that sort of thing is actually important. There are lots of verses in the Bible that also relate to it especially in regards to confusion etc.
I will also note, that I believe that in the long term that I think the notion of united church was something that was impossible in the long term of things. If you go back in time, to before Christianity was legalized, to afterword Christianity had exponential growth. But in the early days, Christian on a given city liked to meet together for worship because they were "one body" And they soon outgrew where they worshipped at because of this. But this sort of thing was OK, because the early church also followed the early Jewish customs regarding things consecrated to God. Basically the early Christians, especially the rich folk would give up their homes and other properties so their would be a dedicated church / sanctuary to meet at. But in the old Jewish tradition that you can see in the book of Deuteronomy things that are dedicated to God cannot be take back for common use. So anyway, when the local church moved out of one place to another, the older building still stayed in service as a place for believers of that area to still use and meet at like a local chapel, parish etc. compared to the cathedral where the whole city tried to worship once a week. But eventually as things kept going it was impossible to find a building to house everybody, so at that point the Christians of the area accepted the idea of multiple services in an area at different locations and times.
Anyway you got something similar with thee Church. Before the days of modern communications like telephones, email, TV and so on. It would really be difficult to eventually be impossible to have a united church, when you have people spread out over thousands of miles: from Africa and Asia Minor, into Europe, into the rest of Asia. Besides dealing with large bodies of water, mountains and deserts etc. as far as barriers to sending messages you got bandits, not to mention nations and empires being at war with each other and considering anybody from the outside or the hostile nation or empire an enemy including people who are clergy, messengers etc.
But of course the real issue is human nature. We get many blessings with Christ's sacrifice, but the one thing we do not get is a renewed mind, we have to work for that, as well as to in general be conformed into the Image of Christ and well when that doesn't happen it causes problems like division.
