I am an atheist while my wife is very religious. She also teaches religion to my son. I teach secularism and evidence based thinking to my son. He is 8 years old. I was wondering if 2 conflicting teachings are healthy for a child? Something in me says it's the right thing to do, but I am also worried if my son gets stressed with all this? What you people think should be the best strategy? One good thing is, luckily unlike other kids out there, my son isn't brainwashed because I trained him enough so he seeks evidence.
This is not the first time this issue has been raised on this site. I agree with others here who say as long as you teach him critical thinking and to question he'll figure things out for himself. I think the potential stress for your son comes in the form of how you and mom handle yourselves. If you present yourself rationally and are not dictating to him and leaving him free to think about things and form his own opinion (evidence/fact-based), then you, at least, won't be causing him stress. If mom is teaching religion as absolute fact it will raise questions in his mind. If you were both on a mission to "win" him over to your way of thinking things could go south in a hurry.
i think exposure to whatever he seeks out, knowing what you believe needs to be nourished. I think you need to be open to his thoughts about your beliefs just as you and your wife need to be open to each other's (obviously if you are building a family with these conflicting beliefs).
Best of luck to you and the exploration!
My ex-wife, the mother of my three sons, became a "spiritualist" (spirit medium, psychic advisor, etc.) when my sons were still young, after our divorce, while I became an atheist. My sons lived with her and I picked them up on the weekends. None of them bought into her spiritualism, though still loving her and respecting her otherwise. They thought what she was doing was weird. Now, as men, two are atheists and one is an agnostic.
As to how to work out your dilemma, only you can figure that out. I was careful to never talk bad about their mother, though not agreeing with her ideas.