I can't seem to find that in my catechism, Brother...
The Catholic/Orthodox/Main line Protestant churches agree on far more tha the disagree, hence why we can work well together in ecumenical organizations and such. There few obvious exceptions among individual memebers who seem to favor conflict. But the True Chritian faiths work well together, most recognizing each others Baptisms, marriages and such.
For example I was raised Methodist, converted to Orthodoxy in my early adulthood and the Church accepted my Baptism in the Methodist faith. You can get too much further apart than Methodist and Orthodoxy in the scheme of things, but we are on the same basic page.