In this one and only Church of God from it's very beginnings there arose certain rifts, which the Apostle strongly censures as damnable. But in subsequent centuries much more serious dissensions appeared and large communities became separated from full communion with the Catholic Church -- for which, often enough, men on both sides were to blame (Catechism of the Catholic Church, par. 817)
I didn’t used to think much about it. Truthfully, I was so used to the idea that Christianity existed in a fragmented state, that it didn’t bother me. Like kids growing up in a broken home. At first it may seem impossible that dad isn't coming home. After awhile it seems natural.
Oh, I knew the Church had been divided when the Coptic Church separated in the 5th century over the Council of Chalcedon. I knew the Church was divided again in the 11th century between Catholic and what we now think of as the Eastern Orthodox churches. I knew the Protestant churches had broken away from the Catholic Church in the 16th century and since had splintered into Lutheran, Presbyterian, Baptist, Anglican, Methodist, Brethren, Congregationalist, Nazarene, Church of Christ with multiple variations within each of these and a thousand other Independent Christian fellowships.
I knew that these Churches were not united, that they contradicted one another on many points of doctrine -- even in their moral teachings. I viewed this as unfortunate, but as something for which there really was no answer. After all, these churches simply don't agree with one another on what the true teachings of Christianity are. And since (in my view as a evangelical Protestant) there was no spiritual authority on earth to decide these issues and unite all Christians in one Church, what could be done?
It was just the way things are.
In fact, it wasn't until many years later that the prayer of Jesus recorded in the 17th chapter of John's Gospel caught my eye.
My prayer is not for them alone [referring to his disciples]. I pray also for those who will believe in me through their message, that all of them may be one, Father.... May they be brought to complete unity to let the world know that you sent me and have loved them even as you have loved me.