How should I handle this situation?

Background: I was raised Christian. I am currently a atheist leaning agnostic; agnostic only because I think there is simply a level of existence and history that we simply cannot claim to know. But I don't believe in a personal deity or intelligent design, etc. My ex-wife and mother of my children became something of a Satanist after we split. Long stories abound here and I can give further detail where you think it's relevant. My ex and I have an agreement that is mutually beneficial, imo, to the wellbeing of our children. She doesn't want them exposed to Christianity and I don't want them exposed to witchcraft and whatever else she believes in. My kids are 8 and 5 and my step daughter is 11. We are currently going through a divorce which also makes me extra careful about over reacting or pushing any buttons because there is a risk that she will move out of state. So there's a delicate balance there that motivates compromise.

The Problem: Although I've talked to her about this several times, my mother likes to push her beliefs. Over the weekend I was out of town and my kids had a sleepover at my mother's house. My ex sent me a text talking about how my mother gave one of my kids a book about Jesus and now she thinks he's real. She's 8 years old. She doesn't have any tools on which to divide factual information from hearsay, rumors, etc. With little kids you often have to teach them that what they see on TV isn't real and is created by computers. What my mother has been told is that it's not that they are never allowed to be exposed to Christianity but that we wanted them to be at an older age where they have more objectivity and understanding; when they're not just going to believe whatever you tell them because of who it's coming from.

So.....

Now this puts me in a position where I feel like my hand is forced. I think it is unrealistic to try to shelter them from religion entirely, but at the same time most sources of religion believe it 100%. In fact, part of their religious ideology is that they have to have faith which underscores and highlights the lack of evidence such that one should never expect that the evidence will corroborate the stories. And so she will never get the whole story from my mother, only the parts of the story that Christians choose to believe. And while that's okay for them, it's not okay to me. If she's going to be exposed before she's ready now I feel like the only way to really fix it is to give her the whole story or at least as much of the other side of the story equal with the amount that she's heard on the side that believes in Jesus.

Whether Jesus existed is debatable. I think he did exist. However, what's far more debatable is who he actually was in relation to the story. No matter what I say in response it may seem like I'm reacting by pushing a personal belief or bias. I don't want to do that. But I don't want to leave her with only one side of a story where now her mother might feel like why not do the same with satanism or witchcraft. These are complicated subjects and everyone seems to get defensive about their own beliefs. And even if I warn her against things which aren't falsifiable; meaning that "hey, people can say anything as long as part of the story is that you can't disprove it." that's still more or less a kind of faith in science and reason in a world in which we cannot completely disprove the existence of any deity. And if she simply WANTS to believe it... just like her grandmother wants to believe it and wants her offspring to as well, then again, that opens the door to what others including myself WANT her to believe.

Any suggestions?

Just an opinion, it's hard to approach for sure; but I think education is now vital. I (again opinion haven't been to this point with a child), I would begin showing her some more and different texts and as young as she is the explanation that here are these texts that explain to people in manner of speaking something bigger than themselves. But, there are a lot of different paths, that each of these explain, even science has theories and questions. So, act as indifferent but she has to be exposed to the reality of different types of religion/faith/codes of life. So, that she can make an informed decision when the time is right. You're going to always want to have her believe in what you want her to. The thing is you just have to accept what she comes to on her own. Thing is if she does think of it now she will think of it in the future when she has gotten older. All of us have, right. Just my humble opinion.

My own opinion .
I am Jedi 100 percent . I subscribe to the ALL MYTH . I know who I am . I can only do what I am capable of. Some days I am cable of more. Some days I can learn to do more.
Now , there are many many MANY stories of small examples that make big differences. Many movies stories and myths use this idea. So many small examples of true dedication to the same idea to make the greater change. I used to wonder and say in my head what could I do ... Little Ol me. Yea , I stopped asking and began to do... Act . Now , long story short ... I am able to be the constant my family needs and my friends. I am the light that needs to be seen. Some need to be see any way lol . All joking aside , life is full and some times we can't have "controll" of a lot of things we like , I know I would love more but rather than let it keep you down and bum you out , sounds to me brother your family needs dad and you rather than labels . Try the dad label on as who you are ... Harder to do than say but possible . Put on the dad as ... You , for me it's .... I'm a Jedi I'm a dad Ima Decon knight I'm a all that and a dad so how would I act like that dad I want or that brother I want to be. That light ... Wow I can only speak from experience ... That light when you become all of them ... All of you )... Things change !

I'll tell you this strait , that situation sucks bro. When it come to our legacies ... Man it's like exposed nerves. Even breathing on it hurts it's so fragile . Children ... How do you keep them safe and from harm...

Ever read the Harry Potter series? I was floored when I got the new continued story and Harry and the wizard are talking . Without revealing much he asks the wizArd how do I keep my son safe ... How are you asking me ... How do I keep a child safe ... I can imagine the look the old man gave him. He said ..."you ask me of all people... How to protect a boy in terrible danger ( no implication your family is in any danger any way just as an example) we can NOT ( my emphasis) protect the young from harm. Pain will and must come ."
Harry says what am I supposed to do just watch ? The wizard says ..." No , your supposed to teach him how to meet life."
The potter series is my wife's thing. One of 123 reasons I love her and can actually name . Now when I read that .. It was like a light hit . Insubcrine to the ALL MYTH . Every Myth for every man. This light I found was so Georgious glow. I glow it now as we speak. I won't ever tell anyone what to do , not my cup of tea . What I can say is this is what Hapen to me. It changed me, on the inside. It helps. I hope that helps . We can't be there every step in every second , impossible and don't worry your self doing that, very harmful to the mind body and soul if we try and continue to worry like that, I think that's where wrinkles come from! Pm me if you got any questions friend and may the Gorce be with you every where you seek it

You have a big problem indeed imo , by denying both of you to share your faith with your children you have set yourself up for failure in inter-human and family ,relationships , i think its the childrens mothers good right to explain what she believes in , and your good right to explain what you believe is and , if you want your kids to have a good relationship with their Nan she should be allowed to share her religion aswell , i would advice you to have a bit more faith in your children , i was brought up inter religious with one side telling me Jezus was a liar and the other that Jezus was the Messiah , and family members that were claiming they were clairvoyant etc , its part of life , your kids will pick a lot of this up at school etc , when your daughter comes home with a book about Jezus , leave it in the middle if Jezus exsist or not , you and your ex both have no right to ask the other to not talk to their children what moves you. Its a paralizing argument and obviously causing unneeded conflict. But that is just my opinion ...

If you push your beliefs on your children, what makes you different than others?

Parents are the primary educators of their children. It is not the states responsibility, the internet, TV or their peers’ job to do… it is the parent’s responsibility.

Informing your children of your beliefs is not pushing something on them. Offering a counter view to one being given them is the best thing one can do. Just make sure to do it in a manner that does not scare the crap out of them or confuse them. And remember, children learn a lot by the example we set.