I have met several people who give me this vibe (and it does trouble me greatly), but I can’t say that most non-Catholics I’ve met give me this impression. Some of my Protestant (e.g. Mennonite and Lutheran) friends seem to be aware of the importance of communal, doctrinal unity – and they do adhere strongly to the faith articles of their communion – while others (the more non-denominational kind) seem to give little thought to the doctrinal unity of Christendom at all.
Personally, I think this is a step down, not up. Christians should face up to the reality of doctrinal disunity in Christianity and actually engage in testing and discussing these tough issues with integrity, honesty, humility, and prayer: the problem isn’t going to disappear if we just throw up our hands and say “Oh, bother with all this doctrinal disagreement! What’s really important is spreading Christ’s message!” It is only a cop-out disguised in false ecumenism which both liberal Catholics and Protestants are guilty of peddling. The Church of the New Testament didn’t operate this way and the neither should Christianity today.
b) Catholics who presuppose that non–Catholics are to be scorned and derided?
Among faithful Catholics, this especially annoys me. There are many, many Protestants who are just as un-formed as many badly-catechized cradle Catholics; these people aren’t all Martin Luthers and John Calvins. If you plan on winning converts, win them with apostolic Truth tempered with Love, not by shoving dogmatism and triumphalism in their faces.
c) Orthodox Christians who are opposed to everything in Western Christendom?
Unfortunately, I have not personally met any of my brethren of the Orthodox churches. I have read a few Orthodox authors in online sources, and I do sometimes get the East vs. West vibe, but I am not confident in my reading of them to say whether that is a major stumbling block.
d) Ill–informed Protestants who misrepresent the Catholic Church and its teachings?
I’d say this is a substantial problem, no less than the problem of some Catholics stereotyping Protestants as “Me, my Bi-bull, and the Holy Ghost!” ultra-individualists.
e) Poorly catechized Catholics who give a false impression of what the Catholic Church teaches?
When nominal Catholics aren’t serious about their own personal devotion and faith, this may give the impression that the Catholic Church teaches a salvation that comes just by going through the motions without any thought to the individual’s spiritual state. Thinking outside of this, my Protestant friends either ignored the doctrinal views that I adopted in my conversion and gave a generic “That’s awesome: go wherever God leads you” or they expressed honest contentions with them.
We should take great pains to avoid misinformation on all sides. Still, misinformation can only explain so much; I’d say down under all the clutter of misinformation surrounding many doctrines, there is a real and honest contention with each of these doctrines that needs to be addressed.
f) Extra–biblical doctrines?
By the time all Christian communions figure out and agree on exactly what these are, we will probably have achieved unity.
Assuming a desire for unity, what is the best strategy to adopt? Who should take the lead? Are “Agreed Statements” helpful or unhelpful? Are Catholics more likely to find unity with those who parted company with the Western Church as a result of the abuses that led to Reformation or should Catholics seek first to unite with Orthodox Christians?
I think the Western Church has a decent shot at reunification with the Orthodox, the immediate successors of Luther, and the Anglican communion as long as charitable discussion and debate are pursued, always keeping in mind the goal of unity. I think there will be much greater difficulties in reuniting with the children of the Radical Reformation.