Quote 1
"I've come at last," said he. "She has kept me out for a long time, but I have got in at last. Aslan is on the move. The Witch's magic is weakening." (10.36)
When Father Christmas appears in Narnia, it is a sign that time has begun to pass in a normal way again. The endless winter is being transformed into normal, human, cyclical time with landmarks like holidays.
Quote 2
"And the dagger is to defend yourself at great need. For you also are not to be in the battle."
"Why, Sir," said Lucy. "I think – I don't know – but I think I could be brave enough." (10.46-47)
Lucy will one day be known as "Queen Lucy the Valiant," and we think she probably would be brave enough to fight in the battle. However, according to Father Christmas, she shouldn't fight because she's a woman. Hmm. We're more concerned about the fact that she is a young child...
Quote 3
"Why, it is she that has got all Narnia under her thumb. It's she that makes it always winter. Always winter, and never Christmas; think of that!" (2.39)
The Witch's power disrupts the symbiotic relationship between the natural rhythm of the seasons and the man-made rhythm of holidays like Christmas.