Spirit of Christmas
In the first few years I was helping Santa with his mail, my letters were all stories of North Pole adventures. When I received a letter from a distraught mother whose eleven year old son was being tormented by peers because he still believed in Santa, I knew it was time to write the Spirit of Christmas letter. It has been one of my most popular letters every year since.
Santa starts out by inviting the recipient to sit down with a cup of hot chocolate because "there are important matters to discuss". He acknowledges that the child is older now and the simple explanation of the 'jolly old man in red who delivers gifts on Christmas Eve' will no longer do.
The letter emphasizes that Christmas is about giving and has the child reflect on how much joy he/she gets when he/she gives a gift. He implores them to always keep Christmas special for the younger children.
I have sent this to children as young as 8 and as old as 80. The message is classic.