Right, so Charlie Brown is frustrated with commercialism and asks if anyone knows what Christmas is all about, and Linus replies by quoting the Bible, reminding Charlie Brown about the religious significance of the day and thereby guarding against loss of purpose. (In our state of knowledge, we don't regard religious observance as a legitimate purpose, but conditioning on the premise that Christianity is true, it would be important to make sure your holidays remain being about Christ, rather than wandering off and becoming about gifts or something.)

I like the indirectness of Linus's reminder (the scene would have been much less effective if Linus had just said, "Well, it's about Jesus"), which is why I referred to the Eliezer's "twelfth virtue" in my (apparently still too opaque) attempt at explanation above. Mere words can only be pointers; they don't in themselves contain the complexity of a thought. The thoughts that you can only invoke indirectly are important. ("You may try to name the highest principle with names such as 'the reason for the season,' 'the true spirit of Chirstmas,' or 'God's word,' but what if &c.)

I like the seeming incongruity of using a religious quote in a Rationality Quotes thread, which on a meta level illustrates that specific ideas can be accepted or rejected on their own merits. Of course Christianity is false, but if a religious quote also demonstrates something true or useful, the irrationality of the source doesn't matter.

Maybe too subtle (judging by the downvotes), but I'm not so sure.