I always try to focus on topics that truly matter. Topics sometimes tend to have a gray area attached to them. When the Word of God is interpreted in its intended literal form, confusion ceases to exist. When something is not explicitly described, we use the Holy Spirit as our guide to make a moral judgment. One such topic in question has to do with marriage and whether or not a Christian can be married a non-Christian.
For the vast majority of cases, the answer is a resounding NO. This is explicitly discussed in Paul’s letters to the Corinthians. He cites two cases. The first case, which this is my interpretation but it seems evident, states that if a couple were to marry and sometime later one of them becomes a Christian that they do not have to get divorced. In this case, you can be married to a non-believer but I find this to only be representative of a minority of marriages. Here are the verses providing evidence:
1 Corinthians 7:12-14 But to the rest I say, not the Lord, that if any brother has a wife who is an unbeliever, and she consents to live with him, he must not divorce her. And a woman who has an unbelieving husband, and he consents to live with her, she must not send her husband away. For the unbelieving husband is sanctified through his wife, and the unbelieving wife is sanctified through her believing husband;
There is one of the exceptions. The majority of cases are where a Christian wants to marry a non-believer knowingly. Paul is clear about this as well. Here are the verses:
2 Corinthians 6:14-16 Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? And what concord hath Christ with Belial? or what part hath he that believeth with an infidel? And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people.
This is a warning to Christians who knowingly choose to marry non-believers. It can lead to the corruption of your soul. I know there are some that would say, well I can lead them to God through our marriage. If that is your rationale for marrying someone, you should be very careful and I would advise against it. A marriage is sanctified and kept whole through God. There will be an eternal division between both of you if that kind of marriage moves forward.
Lastly, this is clearly not a Scriptural opinion but I would even caution Christians who are on polar opposites of the denomination spectrum to be cautious as well. The values held by Protestants versus Catholics are very different. The foundation is similar but not precise. The same would go for Christians and Jews intermarrying. Again you have a situation where both of you ARE believers, if the Jewish spouse does consider Jesus as the Savior, so I would say that it is not unbiblical but should be cautioned. Like with all things, make your decisions on what the Lord condones, and that is especially important with marriage.