Mental humility, it may be said, is the greatest quality lacking in the sporadic Protestant sects and cults ever springing up in our midst. Their self-confident assumption that they possess the truth, the whole truth, and nothing but the truth gives their witness a pioneering zeal at the start but makes them ridiculous in the end.
Ralph W. Sockman (1889-1970) American Methodist clergyman
“The Open Mind,” Protestantism: A Symposium, ed. W.K. Anderson (1944)Full text.