My apologies if I am reading more into your post that you have intended to convey, but, based on the fact that you once reacted to a posted video of "Black Israelite" thugs openly proclaiming their hatred of - and desire to eradicate - the white race by blaming "Luther's Bible only religion" (https://www.cathinfo.com/general-discussion/black-racists-call-for-genocide-of-white-people/
), I don't think I'm too far afield here.
While Heresy creates the very worst
kind of division among peoples - which is to say, cleaving some people from the Truth of Christ, and grafting them into the Falsities of Satan - it is by no means the origin of all divisions, nor would it be correct to assume that all division of peoples on Earth is evil, lest we adopt the Masonic error of egalitarianism, and make God Almighty the villain of the Tower of Babel story.
Division of people by the sexes is the most fundamental and universal - there are also divisions by age, by social status, by language, by ethnicity and, yes, by race (indeed God Himself made that last division explicit by physically separating the races first geographically, and then by physiognomies and psychologies suited to those geographical placements).
As for the unity of Catholicism. Yes, the Faith brings us a spiritual unity which will one day result in true, total unity for the elect in heaven. On earth, however, divisions remain. Look to Catholic colonial societies in places like Africa and Haiti. In Haiti both the black African slaves and the white French masters were Catholic, but the racial differences kept their society very much divided. The French government's ban of miscegenation in its colonies codified their explicit desire to keep their society divided along racial lines. The fact that this ban was only revoked after
the Catholic Monarchy of France was overthrown by egalitarian Masons
is a most salient one for modern Catholic reflection, in my opinion.
While America's official position of religious indifferentism is sufficient all by itself to doom this county to spiritual death and fundamental lack of cohesion, the fact that this country doubled down on its Masonic egalitarianism by attempting to integrate a large sub-Saharan African population into its national fabric - and continues to do so in the face of literally centuries of proof that this endeavor is impossible - shows that it is the broader egalitarian and indifferentist
errors - rather than the particular heresy of Protestantism - which is the root of America's many, ineffaceable divisions.