What is your main feeling in wanting to take your children? Is it still the cultural education thing? The sense of occasion, the experience of a carol service?
Or is it that you would like them, in your heart of hearts, to share your faith, that you want them alongside you in your relationship to your God?
If it is the second there is a battle of ideology going in with your kids as the fulcrum.
I am positive about DC experiencing cultural and religious beliefs, but I become uncomfortable if DP ever tries to instil a particular approach that I do not agree with, whether it be politics, moral arguments or whatever. "M1 believes this, M2 believes that, isn't it interesting that we all think different things and can make different choices" is fine. Pulling different ways is bad.
If it is purely the cultural experience (and inevitably an introduction into a church context within which your kids can make up their own mind) then your DW is being unreasonable, controlling, and / or not trusting you that this is the case.
If you are secretly or unconsciously hoping to actively influence the DC then there is s different problem.
Have you considered couples counselling to talk through how you both handle this aspect of your relationship? Not Christmas specifically, but different beliefs?