But consider how each sect defines unity and the criterion for uniting to others. In my mind, to simplify:
Evangelicals: we must agree to a common *subset* of beliefs
Catholics: we must agree to allow contradictory belief systems under the primacy of a single “politically” unifying belief
Orthodox: we must agree to unite under one belief system
The Catholics' willingness tolerating diverse beliefs under a single universal shepherd is key. A return to conciliarism (vs. a single pope), which was already the political system in the Catholic Church historically, at least for a time, could be one path to greater unity. Gets around Protestants' reticence to submit to the Pope and sidesteps the issue of papal infallibility.
