See here.
-A8
Perfect agreement on every issue, no matter how tiny or mundane, is impossible. We fallible humans have minds of our own. So where draw the line? The Roman Catholic Church has institutional unity, but its members, even among its bishops, hold a variety of views as wide as Evangelicals might.
The path to Christian unity ends with institutional unity. Two religious groups cannot be stitched together from the top down, they must grow together from the bottom up. In that regard, Traditionalist Catholics and Evangelical Protestants have come a long way- particularly in addresses the issues of today.