That is something that all of us, if life goes according to plan, will go through. My Father passed in 1995 and my mother in 2005. Everyone reacts differently to that. My Father died in August and my Mother on the last day of November. She was closer to the holiday. She used to always have a Christmas Eve get together at their house before and after my Father passed away. My sister felt the obligation to continue the tradition as have my children. We still get together on Christmas Eve as well as on Christmas Day.
I am a type of person that easily accepts death as all part of the experience of life. It happens to all of us, so even though I miss people that have gone, I understand that it is part of life. My sister is much more emotional about it and for the first two or three years after my mothers passing, on the table with all the party goodies was a picture of Mom with candles, sort of like a shrine. I have to be honest... I understood the reason the first year, but, after that it just got disturbing. Nothing will take the fun out of a party faster then being reminded of death. My mother also always gave me a box of chocolate covered cherries every Christmas. My sister insisted in sending me the same thing, all wrapped up and signed "From Mom". I didn't want to hurt her feelings, but, that to me was downright macabre. It continued until I found a way to let her know that she no longer had to continue that because my daughter made homemade Cherry Cordials for me every Christmas and that I was having enough problem trying to get my weight down that I didn't need more chocolate.
So the first Christmas is very strange, but, if you feel that they are in a better place, then we can and should honor their memory but in a positive and happy remembrance if we can.