The spirit of Christmas is about giving as
The Gospel of Matthew (2:1–12) speaks of Magi, or wise men, who followed a star from the East to Bethlehem in search of a newborn king. There they found Mary and the baby Jesus and offered him gifts of gold, frankincense, and myrrh.

When your children find out that Santa Claus is actually other family members you let them know that now they have become a Santa and to continue to give to the innocent and younger ones as the three wise men did for Jesus during his birth.

Just trying not to remove all the positive things about Christmas and giving.