St. Clement, in his letter to ”the Church of God sojourning at Corinth,” writes:
“Why are there strifes, and tumults, and divisions, and schisms, and wars among you? Have we not [all] one God and one Christ? Is there not one Spirit of grace poured out upon us? And have we not one calling in Christ? Why do we divide and tear in pieces the members of Christ, and raise up strife against our own body, and have reached such a height of madness as to forget that we are members one of another? Remember the words of our Lord Jesus Christ, how He said, Woe to that man [by whom offenses come]! It were better for him that he had never been born, than that he should cast a stumbling-block before one of my elect. Yea, it were better for him that a millstone should be hung about [his neck], and he should be sunk in the depths of the sea, than that he should cast a stumbling-block before one of my little ones. Your schism has subverted [the faith of] many, has discouraged many, has given rise to doubt in many, and has caused grief to us all” (ANF01,1 Clement, Ch. XLVI).
I’m pretty sure he would write this to the modern North American church too.