Inharmony is a deplorable offense in the case of Christians, putting them in the worst possible light and making it impossible to steer clear of factions. Divisions are an offense to the world's wisest and best, who cry out, "If the Christian doctrine were true, they would preserve unity among themselves, but as it is they envy and slander and devour one another." For, though the world carries its on great beam in its eye, it cannot refrain from judging us for our mote, and thus exalting itself as if it were pure and beautiful.
Martin Luther, "Sermon on 1 Corinthians in Sermons of Martin Luther, Vol VIII, 1909" quoted in "For All the Saints" page 1030