Religion in and of itself doesn't really matter that much, only what it entails.
Someone who is religious, is superstitious, and that's what you should care about.
When someone says they believe something on faith, it's not necessarily what they believe that you should care about, but the fact that they believe something on faith.
Faith is believing something without evidence (or "pretending to know things that you don't know, or know you don't know")
Faith is a rejection of reason, logic and evidence, and should therefore be rejected, and shunned.
Another objection is that a religious person will hold the supernatural, and/or supernatural being (god) as more important than you. If for you there is someone more important than me, then have a committed love relationship with them, and leave me out of it. I am the most important person to my wife, and she is to me.
My biggest objection to (some/most) religious people, is that they believe in a hell, believe that non-believers go there, and worship the god that is going to send them there.
I could not be in a romantic, sexual or even friendly relationship with someone who believes that I am going to hell, and worships and/or claims to love the thing that is going to send me there. To claim to love or like that person is a rejection of myself.
I would only ever marry an atheist, but not because they are an atheist, but for why they are an atheist. If they are an atheist for bad reasons, and those bad reasons (could even be based on faith) are things that I should reject, I couldn't accept it. I wouldn't marry someone because they are an atheist, but because they'd have the correct foundation where that atheism is built on.
What it comes down to, and I think Stefan would be perfectly in line with me saying this: Principles.
If you apply principles (logic, evidence, reason and morality) to anything, the result would be Atheism, Anarchism, Capitalism, Peaceful Parenting (I guess the most important 4 "positions"), etc.
So don't choose someone because they are an atheist, but for how they got there, and of course don't judge someone based on just one of their positions.
An atheist who 'worships' the state is not someone who strictly follows or applies principles to everything, so even if they arrived at atheism for the right reasons, that doesn't make them 'good enough'. Although, a person who has arrived at many good positions for the right reasons, would probably be easily convinced to change their mind on the things they haven't gotten right yet.
Stefan's wife was a Christian when they met, and I don't know the story, but I'm assuming that she was easily convinced/persuaded of Stefan's arguments against religion/faith for the right reasons.
Hope that helps