The Bible is clear that a Christian should only marry a Christian. We gather that from where the Lord warned the people of Israel not to "make a covenant with the inhabitants of the land to which you go, lest it become a snare in your midst" (Exodus 34:12). Also, Paul instructs us not to be "unequally yoked with unbelievers" (2 Corinthians 6:14), and he reminds the widow that she is "free to be married to whom she wishes, only in the Lord" (1 Corinthians 7:39). Certainly this wasn't intended to squash our love life, but it's intended by God for our good. I can remember someone once telling me about their non-Christian spouse, how exceedingly sorrowful it was to wake up every morning next to a spiritual corpse. Indeed, I can think of few things more burdensome in this life than to be unequally yoked--to marry someone who doesn't share convictions on truth, life, and eternity.
But I've also encountered people who thought they were marrying a Christian only to wonder, sometime later, if they'd been mistaken. From my limited experience this isn't as uncommon as we might think. As we slip into the day-to-day routine of life, share in its hardships and trials, as we become more known to our spouse, we sometimes wonder what happened to the person we married. It happens in many ways. From the bride who told her friends she was marrying the "godliest man she had ever met," only to find out that he's not that passionate about godliness, to the groom who wonders why his wife's enthusiasm for theology and doctrine isn't in lock-step with his. Or the wife who can't figure out why a man who seemed so gentle and kind--bearing the fruit of the Spirit--is actually annoyed and angry all the time, and the husband who doesn't think his wife displays a life of repentance. Or the woman who yearns to be washed in the water of the Word but whose husband gives no leadership, or the man who watches his wife's zeal and passion crumble in the midst of tragedy, loss, or depression. If we're honest, and it's almost embarrassing to admit, sometimes we begin to wonder, maybe my spouse isn't the Christian I thought they were. So what do we do in a situation like this?
Well, the sad reality--and I don't want to minimize or maximize this--but the sad reality is that you _may _have married a non-Christian. It was Jesus who taught that there would be those who received the Word with joy, but they do so as those without roots and so they will not endure. Still others will have the Word planted only to be choked out by the cares of the world and the deceitfulness of riches. Is it a possibility your spouse is one such person? Yes. But, for the sake of charity before you even think those thoughts, here's a few suggestions.
_First, _seek repentance in your own life. Jesus' instruction is as applicable to marriage as any other relationship, "Why do you see the speck that is in your brother's eye, but do not notice the log that is in your own eye?" (Matthew 7:3). Could it be that you're being uncharitable, overly judgmental, setting unrealistic expectations, withholding forgiveness, blowing things out of proportion, harboring bitterness and frustration in your heart, etc? Then seek repentance in those things and be reconciled to your spouse.
_Second, _search the Bible. I know I have a bit of a pessimist streak in me, but I tend to think that one of the great(er) points of confusion among many today is what a "Christian" actually is. At times we have a tendency of making Christianity _more _than it is. We think _all _Christians need to think, act, feel, speak, behave, and express themselves just like me. There's a threat in this to our marriages. Why? Because the mystery of marriage is that it invites us into the reality of _two _people--sinners nonetheless--trying to be one. You are not your spouse and your spouse is not you. So don't use your personality, your wants, your gifts as the standard of what it is to be a Christian. Go to the Bible and see what it says.
_Third, _live a Christian life. The Apostle Peter wrote, "Likewise, wives, be subject to your own husbands, so that even if some do not obey the word, they may be won without a word by the conduct of their wives, when they see your respectful and pure conduct" (1 Peter 3:1-2). And Paul said, "The unbelieving husband is made holy because of his wife, and the unbelieving wife is made holy because of her husband," and then asks, "How do you know, wife, whether you will save your husband? Or how do you know, husband, whether you will save your wife?" (1 Corinthians 7:14, 16). As one person commented, next to the Word of God there's nothing so powerful to win others than our lives. If you're burdened by the thought that your spouse may not be a Christian, live in such a way that Christ is reflected in you.