Do married partners' religious beliefs need to be the same?

I had this discussion with a friend of mine today. We have been discussing all things religious over the last few weeks since I shared with him that I am leaning towards atheism.

My friend spoke of the importance so many couples place on sharing the same religious beliefs. When I asked him why this is, he proposed that it's about both partners sharing a common set of morals, and being able to bring their children up to share those morals.

I'm not convinced. I'm convinced that this may be why so many couples put an emphasis on sharing the same religous beliefs, I'm just not convinced that it is necessary. I am somewhere between agnostic and atheist. My wife is Christian. Let's compare our moral set: My wife believes in the importance of us being honest with one another. So do I. My wife believes in the importance of being kind to others. So do I. My wife believes in sharing with others. So do I. My wife believes murdering an innocent person is wrong. So do I. My wife places a priority on respecting her parents. So do I...

This list could fill many, many pages. It seems to me that when the list of our moral beliefs is complete, there will be some, but few, differences. And they will not be based on our respective religous beliefs. Believing in the importance of being good to others does not require a faith in a god. This is a myth. And so, I'm left to make the following comparison: Is it crucial that two married partners agree on whether or not aliens exist in other galaxies? Is it crucial that married partners agree on whether or not humans will be able to achieve time travel in the future? Is it of the utmost importance that married partners agree on whether or not a cancer vaccine will ever be made? These are all questions that we cannot answer with certainty. It's a matter of opinion. Why would we place such a high priority on two partners agreeing with the same opinion?

Aren't religious beliefs really opinions? Of course many religious individuals would argue "no," because they are convinced that their religion is the one "true" religion. But it is a matter of opinion. Did husbands once leave their wives upon hearing that their wives doubted the existence of Zeus? Probably. Have husbands had wives killed who have expressed doubts in the teachings of the prophet Mohommed? Likely. Have engagements been broken because a Protestant man refuses to convert to Catholicism? Definitely.

If this really is about moral codes or values, what about the value of respecting the one you love enough to allow them the freedom to form their own opinions, and not insist that they be just like you?