Rituals don’t have to be religious or related to religion. Daily regular, repeating activities are rituals - even without any link to a religion.
Does your Christmas have a direct relation to Christianity? It can be celebrated as a social and societal construct, possibly with imagery and rituals, with or without actual intention and relation to the religion.
Personally, I don’t think I’ve ever experienced Christmas as a celebration of god and Christ in the direct and factual sense. Thinking back, we had the stories of birth and my mother even tried some singing with us. I don’t think I’ve ever taken the stories for fact though. It’s a setting, a story, a celebratory setup. (But I wonder if that may be back-looking reinterpretation with a changed mindset. It certainly wasn’t something that stuck over time and after early childhood.)