People take their beliefs personally so it is only natural that people will feel like they are the ones being challenged when their beliefs are what is being challenged and will act accordingly.
It is preventable. If the person whose beliefs are being challenged takes into consideration the fact that his beliefs, not him, are being challenged he can bypass the first part of the statement. A Baha'ullah (the
Bahai prophet) quote say how to avoid the effects of the first part of the statement.
“Should any one among you be incapable of grasping a certain truth, or be striving to comprehend it,
show forth, when conversing with him, a spirit of extreme kindliness and good-will. Help him to see and recognize the truth, without esteeming yourself to be, in the least, superior to him, or to be possessed of greater endowments.”