Christmas Spirit

I need a little advice. My fiancé lost his mother on Christmas Day when he was 11, just about 13 years ago. She was very sick towards the end of her life and he was always there to help her. Sadly a few days before she passed, she sent him away to his fathers house so she could pass in peace. The news was broken to him when he returned home, a few days later. To this day it haunts him, now it’s not our first Christmas together and I know this time of year always reminds him of her. He secludes his feelings although he tries not to but I always catch when something hits a little too close to home. I’ve had this idea of taking him to church on Christmas Day and having him light a candle in her honor, maybe pray to or for her but I’m scared. I don’t want to be too pushy but I think it’s time he “let her go”.. I know she wouldn’t want him down in the dumps and depressed. Any suggestions on what to do?? I would appreciate it tremendously!

P.S. I do not literally mean “let her go” I know this topic is sensitive so in no way would I ever tell him to just let her go, what I meant was, it’s time he stops blaming himself for her death.