Defense is natural. All people, all beings in fact, defend themselves when under threat. There is nothing wrong with this. However, when there is no actual threat, when instead only an idea is threatened, there is a tendency for people to grow defensive if not violent. A great example of this is the defense of religion. Most have been witness to this or even partaken in the event. Perhaps a comment was made by a non-believer. Or, perhaps an individual who clearly does not prescribe to the same ideology enters the room (digital or real). It doesn't take much for people with "strong beliefs" to begin the often insane crusade to either prove the other wrong or show that their "truth" is unshakable.

Why?

If a belief is strong, it needs no defense. Ideas are untouchable. They are only under threat when the believer feels vulnerable. This is akin to a "macho" man feeling the need to parade his bravado in a juvenile effort to appear "tough". Clearly, such an individual is weak. Otherwise he, or even she, would feel no need to prove. The individual's identity is clearly built on a house of cards and so is ready to tumble.

If you feel strongly about something, put it to the test. Take the criticism. Allow others to hold their beliefs without the need to convert them. The truth is strong enough on its own.