I majored in history (which is about as useful as majoring in general studies lol), also dropped out after a few years and is super helpful as a software developer... Anyways what I teach my kids isnt the fantastical parts of Santa, any of that but the history of how that came about. Im a Christian but even with that I want to explain to my kids why I believe that stuff, but Im not going to force it down there throats. I basically believe my job as a parent is to educate them, and do my best to live in a way that I think is right as an example to them, but ultimately let them figure out life and their beliefs and I will just love them and do my best to be there for them along the way. Probably a long winded answer (Im very good at those!)
I'm the wax and your kids are the heat. https://www.bing.com/videos/search?...DB746857B375B826CC8FDB746857B375B82&FORM=VIRE
First gradually introduce them to the concept of infinity. Then, introduce Christ and his teachings that you feel inside are both just and right. Along the way introduce the definitions of morality and ethics.