On this Reformation Day, how should we think about the divisions in the church today, especially between Protestants and Roman Catholics? This is obviously the perspective of a Protestant, but this is my response: When we look back into the pages of church history, or look across the world today, what does this "fracturing" or "division" actually mean? If it means that Protestants and Roman Catholics fight and war against each other, no argument, that is a HORRIBLE thing. But if they don't, what is "missing" in the body of Christ?
Put another way, if the ecclesiastic hierarchy of my Presbyterian church does not have unity with the ecclesiastic hierarchy of another denomination -- or the RCC for that matter -- what's the result? Once again, if it means that Christians in the same city have hostility against each other, that is terrible; but in practical terms, it would be unreasonable to expect EVERY Christian in a decent-sized city to have close relations with each other.
Look at the letters in the NT, and the account of Acts. One local congregation is not put over or against any other congregation. Indeed it is rare for cross-congregational relations to be mentioned, EXCEPT when it comes to simple acts of charity and gifts, of showing this kind of selfless "love" for one another.
Or consider the incompatible practices between Jewish and Gentile believers in the book of Acts, that needed to be moderated by the Jerusalem church. What was the result? Even if you think it was binding to other churches, the result was a compromise, a removing of offenses so that both sides could fellowship (especially eat and drink) with one another. Jewish Christians were not forbidden from circumcision, for example, just forbidden from requiring it of Gentile believers. Gentiles were told to refrain from eating certain things, so that they could eat together with their Jewish brethren.
And indeed the Roman Catholic Church should look to the behavior of those early Jewish Christians. Did they cling to the practices and religious forms that, at the beginning, defined what "the church" was? When those early Jewish churches saw the expansion of the church into Gentile lands, into unimaginable peoples and places, worshiped in new ways and with new practices, did they -- who were once at the center -- fight to maintain their ecclesiastical preeminence or to keep the same practices? Or should the RCC say, like Peter in Acts, "Therefore, if God gave them the same gift as He also gave to us after believing in the Lord Jesus Christ, who was I that I could stand in God’s way?” When they heard this, they quieted down and glorified God, saying, “Well then, God has also granted to the Gentiles the repentance that leads to life.”"
And likewise the Protestant world should not despise the Roman Catholic church. Even if you think that they have "fallen away" in some manner, certain these words from Romans are still true for them:
"But if some of the branches [Roman Catholics] were broken off, and you, although a wild olive shoot [Protestants], were grafted in among the others and now share in the nourishing root of the olive tree, do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you. Then you will say, “Branches were broken off so that I might be grafted in.” That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. For if God did not spare the natural branches, neither will he spare you. Note then the kindness and the severity of God: severity toward those who have fallen, but God's kindness to you, provided you continue in his kindness. Otherwise you too will be cut off. And even they, if they do not continue in their unbelief, will be grafted in, for God has the power to graft them in again. For if you were cut from what is by nature a wild olive tree, and grafted, contrary to nature, into a cultivated olive tree, how much more will these, the natural branches, be grafted back into their own olive tree."