a comment in response to this post (must be a Xangaphile to read)
I'm certainly no Christian, but even so, I think you're undervaluing and slightly distorting their argument (straw man logical fallacy).
It would seem to me that Christians don't get defensive "because they are faced with another belief about why the universe exists." If they are true Christians, their defense stems from the belief that if you (brassmaster) don't agree with them then you are bound to spend eternity in hell.
The argument isn't about simple explanation. The argument, in a Christian's eyes, is a struggle for your eternal life. I allow that people don't like to be wrong (which is why I never am ), but in this instance, the consequences for "being wrong" far outweigh the appearance of defensiveness.
(Christians: feel free to correct me.)
All that being said, atheists have the save argument on their side and, theoretically, should be equally defensive (which, I must say, you seem to be--not that it's a bad thing). An atheist might argue that s/he is in a struggle as a well, a struggle to stop Christians from wasting their only life worrying about a fictional next. Consequently, that could evoke the side kind of argumentative strategy (i.e. the consequences for "being wrong" far outweigh the appearance of defensiveness).
Which, in your case, I believe it has.
Point of this comment: Give an argument the benefit of the doubt before you begin to deconstruct it. Otherwise, on a rhetorical level, you may be arguing against yourself.