Many evangelicals believe that Christians shouldn't date or marry non-Christians. They call this being "unequally yoked." Touched by an Angel did an episode on this topic, which starred Wynonna Judd. Wynonna was a God-believer, and she was about to marry an agnostic. The angels helped put a stop to that!
Personally, I didn't really understand the concept until I watched last night's Eli Stone. Eli Stone is a lawyer who has visions from God, and that has led him to make radical moves on behalf of the oppressed and disenfranchised, plus he no longer kisses up to the rich and powerful. For a while, the head of the firm, Jordan Wethersby, wasn't too enthusiastic about Eli's activity, since his firm made money off of, well, the rich and the powerful. But, during this season, he has embraced Eli's righteous crusade, and he is open to the idea that Eli receives revelations from God.
It's been a hard walk for Wethersby, and that was topped off yesterday when his wife left him. His wife couldn't live with the new Jordan. They were going in entirely different directions. They were unequally yoked. Jordan didn't necessarily want his wife to leave, the same way that Christians usually shouldn't be the ones who initiate divorce with their non-Christian spouse (which is how I understand Paul in I Corinthians 7). But Jordan following the right path inevitably led to their split-up.
Where am I on this issue right now? Personally, I'm not too sure I'd want to be married to a fundamentalist evangelical who loves the Lord, since I have problems loving the Lord right now. I'm hesitant to marry an atheist, however, because I may get to the point where I do love the Lord, and I wouldn't want to find myself unequally yoked at that time.