"What we (or ay least I) do believe is that there is a greater being -one that can't be described using human words ..."
Hmm ... isn't "greater" a human word? And don't you use it to describe this "being"? Does that contradict the "can't be described using human words"?
Avoiding contradiction, you might simply say, "What we (or at least I) do believe is that there is a being -one that can't be described using human words ..." That seems not unreasonable; at least it is not impossible that it be true.
However, you then go on to say, "This being is benevolent ..." But, well, again, "benevolent" is a human word, isn't it? And you use it to describe "this being", don't you? Do you see that this contradicts the other part of your belief, "... can't be described ..."
You go on to use more human words to attempt further what you have claimed cannot be done, viz. describe this being.
I'm sure you will be able to understand this. Equally, I am sure it will not shake your faith. Will it nevertheless help you (and others?) to see the unreasonable nature of what you believe? (Perhaps we all believe unreasonable things ...)
...For the topic of the thread: By all means teach children some people believe in indescribable beings, just as others believe in sky fairies and pixies, angels, gods, whatever. But don't then try to describe these indescribable things. And please leave off - I said to my own children's teachers long ago - with all the baby Jesus stuff. (Some people think it's nonsense, you see ...)
If you want to talk about crucifixion, why not human sacrifice? Huitzilopochtli was a good god for that; let's study him ... or Tezcatilpoca ... or, well, lots more.
Teach children about religion, sure. But please don't be so parochial as to focus on just a few local beliefs: let's hear it for Dis (whom Caesar found to be the chief god of the Celts); Tarves the bull; Moccos the pig; Epona the mare; Mullo the celestial jack-ass ... Zoroaster (one of my particular favourites) ... and so on and so on.
[Some readers will spot I am channelling H.L. Mencken here. If you want a fuller list of gods to teach children about, check out his Memorial Service, (first printed in the Smart Set, March, 1922, pp. 41–42); search for Mencken's 'Chrestomathy'.]