As a follow-up, though, let me add that I do not believe Protestantism has been without sin relative to the issue of unity. Surely, many individual congregations and denominations have 'split' when they should not have; separated over secondary issues or non-issues. John Frame has a lovely book entitled, Evangelical Reunion (Frame is a member of the Presbyterian Church in America and no great friend of mainline Presbyterians). Nonetheless, Frame sets some excellent parameters toward reachieving organic unity on a wider basis than currently exists. I do think it would be better to have three or four "blocks" of Protestants, rather than thousands of denominations. Many Protestants do take ecumenism and organic unity quite seriously. Yet, the era of "denominations" is likely coming to a close and it is a paradigm shift that I suspect will even overtake the Roman communion globally to some degree, just as it is and will affect Protestants.
Folks are gravitating toward likeminded folks regardless of denominational labels or doctrinal peculiarities - by that, I mean orthodox Methodists and Presbyterians have far more in common with orthodox Roman Catholics - even when they debate issues that are leftover from the 1600's, than with 'liberals' or 'fundamentalists' or 'New Age/Mystic' types within their own traditions. So, you find the boundaries of 'denominations' or 'congregations' becoming fuzzier; brand-loyalty becoming weaker and a true spiritual, if not always organic, unity developing between those who confess faith in the triune God and can affirm the Apostle's Creed without crossing their fingers.
First, you chose to read what I wrote in the least favorable light. For instance, clearly my comment about "feelings" when read in context is about one's feelings about what is scriptural - not just about one's feelings.
Second, I agree that those of like mind regardless of their confession are gravitating toward one another.
The author is trying to claim that Catholics have lots of denominations (when in fact we are one united faith with no denominations), and that there are not endless variations of bible Christianity and Protestantism which are not at all united. The author is dead wrong.
Reminder of the obvious for another poster: those who claim to be Catholic and who reject her doctrines are in fact not Catholic.