Depends on how far away on the spectrum you are . My boyfriend claims to be agnostic but more than once we quarreled about the purpose and meaning of life. He strongly beliefs that the morals come from religion and one is impossible without another.I have learned not to push the subject and try to ask him the questions which force him to revise his positions rather than preaching. We are still work in progress..

I got one brother. We respect each other. I don't confront her with that old, I know better than you attitude. I fill like each individual should observe and ask questions. Make there own choice. I go to church with my with my wife sometimes because I love and support her. I just stand and sit. Real simple for me. Always keep from antagonizing a person with your belief and let them take they're baby steps to change. You'll be fine my friend.

It depends on how open minded and accepting the person of faith is.

I voted situational, but now for me there is no possible way i could be with a believer. I find intelligence to be the sexiest and probably a key aspect to a long term relationship, but to be a theist you have to be in denial and basically closed minded, so this would never work for me.

It depends.
She would have to be reasonable about my beliefs and not try to pressure me to convert.
That would be a fast deal breaker for me.

Depends on how vocal you are. For me no, I enjoy debating and sharing my thoughts too much to ever be in a romantic relationship with a Christian.

Faith has no thing to do with Love. However, mutual respect and engaging in each other are more important.

Yes. It requires that you both respect each other's right to believe as you choose and make no conversion attempts or disparaging remarks to the other about his or her beliefs. My wife and I have done it for 23 years.

It would be difficult for me. I have friends who are believers, but to have a partner whose world view is so different from mine would be a challenge and likely mean that some important values differ, too, which would strain our relationship considerably.

Is thought biological ?

Depends on the depth. There are non-practicing all the way to obsessive.

Honest conversation and acceptance and respect for each other can go a long way. You each have to decide what you can and cannot live with.

Every romantic relationship has an element of risk even under the best of circumstances. You have to decide what risks you will or will not take.