I absolutely agree with Rick. It's a nightmare. Don't do it!!
I was saved at 11, but backslid for many years because I didn't grow as a new believer. God had changed me, but it was at a time when there were problems in my church. The pastor stepped down, leaving the church with no leader, and there was a woman that was discouraging to me. I didn't learn and didn't grow at all, so I fell into backsliding.
During the backsliding I met someone and we eventually got married. He wasn't born again, though he identified himself with a particular religion, which he was backsliding from at the time. I was ignorant of different religions and beliefs, so I thought nothing of it.
I came back to God in May 2011 after being chastised 3 times and receiving healing, in which I promised I would never backslide again. My return then lit a fire under my husband and unfortunately sent him back to his religion. The more I grew, the more there was conflict. I knew he was in a false religion.
Believers will always face spiritual warfare in the world, but it's even worse when it's in your own home on a daily basis. Why would you want to put yourself through that? At one point we almost broke up over it. I really believe that if God wanted this marriage to end it would've happened in 2011, when everything reached it's peak. Our foundations were different. I was making Christ my foundation and he wasn't. I was trying to put God first.
Unequally yoked marriages do not work. One is born of God and the other is still in the world, therefore they have worldly desires and do not like spiritual things. One is content and the other isn't. There is a reason God mentions this in scripture and it's important we don't disregard it.
When you throw children into the mix it'll be much worse. I cannot allow us to go there unless he is first born again.
The reason I talk in past tense is not because I'm divorced, but because things are better than they used to be. God is currently drawing my husband and he's becoming more interested in scripture and sermons. We watch a daily sermon on tv and he goes to a weekly bible study at work, which a colleague invited him to (I knew he would meet a christian at work!), so he is being overloaded with scripture. He's more exposed to truth now than ever and I see God working. We often discuss scripture over dinner and he isn't bored like he used to be. Please pray that God continues to work in his life.
I know a woman that rejected dating someone, telling him she would only date a christian. He chased her for a year and then started learning about her faith. He was eventually saved and they are now happily married with a large family