Direct Answer
Based on David Bercot’s teaching, the resistance usually rises at the point where the “literal and natural meaning” seems to contradict what we were taught—especially the assumption that communion is only a symbol. He says we must lay aside the mental habit of automatically inserting “symbolizes” or “figuratively speaking” into Jesus’ words.
Support from Transcript:
Where have you learned to distrust the “natural” reading of Scripture? What authorities (church tradition, teachers, fear of Catholic-sounding language) most shape your instincts about communion?