Linus replies by quoting the Bible, reminding Charlie Brown about the religious significance of the day and thereby guarding against loss of purpose.

Loss of purpose indeed.

Charlie Brown: Isn't there anyone who knows what Christmas is all about?

Linus: Sure, Charlie Brown, I can tell you what Christmas is all about. Lights, please?

Hear ye the word which the LORD speaketh unto you, O house of Israel:

Thus saith the LORD, Learn not the way of the heathen, and be not dismayed at the signs of heaven; for the heathen are dismayed at them. For the customs of the people are vain: for one cutteth a tree out of the forest, the work of the hands of the workman, with the axe.

They deck it with silver and with gold; they fasten it with nails and with hammers, that it move not.

-- Jeremiah 10:1-4

Linus: It's a pagan holiday, Charlie Brown.