History PROVES that the disqualifying flaw; of the One True Church; is in it's insistance that all those who came AFTER them are in error.
"One indeed is the universal Church of the faithful, outside which no one at all is saved, in which the priest himself is the sacrifice, Jesus Christ, whose body and blood are truly contained in the sacrament of the altar under the species of bread and wine; the bread (changed) into His body by the divine power of transubstantiation, and the wine into the blood, so that to accomplish the mystery of unity we ourselves receive from His (nature) what He Himself received from ours."
--Pope Innocent III and Lateran Council IV (A.D. 1215)
The Greek Orthodox he keeps appealing to would disagree.