When you place water and oil together in a glass, they do not mix, but still can be contained in the same glass without any pollution. However, when you introduce another material into the mixture, say, a piece of bread, then you have got a problem. The bread cannot survive intact and will dissolve in both the water and the oil. Then both the oil and water will be soiled by the dissolved bread.
Your marriage is like the water and oil in the glass. The bread, your children. I really cannot offer you any satisfactory solution. It is also a very sensitive issue. Not only both of you have problems, but also be aware that the children will be exposed to contradicting beliefs.
If only it involves water, oil and bread, then it is easy. Leave the bread alone. But can we??