Jonah, here’s a simple solution for your correspondent: The next time he does his training, he should simply say, “You know, someone once said, ‘And why beholdest thou the mote that is in thy brother’s eye, but considerest not the beam that is in thine own eye?’ And that someone, of course, was the Son of God, Our Lord Jesus Christ.” That way, you make your point and nobody gets offended. Problem solved.