It’s my contention that if it’s forbidden for a Christian to marry a non-Christian, then it is at the very least a deliberate walking into temptation to date a non-Christian. If you can’t marry them without a supernatural conversion wrought by the Holy Spirit in their heart, over which you have no control, then it would be both extremely foolish and very unkind to consider such a marriage in the first place.
The Bible says it is sinful for a believer to marry a non-Christian.
1) Genesis 1: Marriage is to display God’s image by obeying God’s commands for fruitfulness and dominion.
In Genesis 1:26–28, God designs marriage to be a partnership in ruling creation under his rule. If we don’t acknowledge that we’re ruling under God’s rule, then we’re ruling under the rule of an idol, or a combination of a whole series of idols.
Practically speaking, this impinges on every single decision you have to make as a married couple. For example, how do you decide what you should do at any point in your life? Should you:
1) do what pleases the Lord?
2) do what pleases yourself?
3) do what pleases others?
For the Christian, number 1 trumps number 2 and 3. For the non-Christian, there is only 2 and 3.
2) Genesis 2: Marriage is a partnership in doing God’s work.
Genesis 2 fleshes this out more. Genesis 2:15–17 shows how Adam is prophet/priest/king in the garden kingdom where God has put him to rule within the constraints of God’s ultimate kingship (symbolized by the two trees: blessing and life for living under his rule; curse and death for refusing his rule). The rest of the chapter details how Adam is incapable of fulfilling his calling to be prophet/priest/king alone. He needs a suitable helper in order to do that, so Eve is provided so that together they will fulfill God’s calling to bring glory to his name under his rule.
Therefore, marriage is a partnership. “It is not good for man to be alone” isn’t true primarily because man is lonely: It’s true because he’s incompetent, even before the Fall.
God did not create man alone to be competent to fulfill his calling to image God. He created man and woman in relationship to do that. Single men and women can do that also, particularly in relationship to the church under the love of Christ, the fulfillment of marriage.
So, in a Christian marriage, marriage is a partnership in the gospel. Conversely, to marry a non-Christian necessarily makes marriage a partnership in something else.
Why would a Christian choose to enter such a partnership?
3) Genesis 3: Marriage is harmed by sin.
Genesis 3 shows how us how marriage gets messed up by sin. Adam and Eve go from naked and unashamed to hiding from one another.
In the curse, God pronounces how marriage post-Fall is a battle of one sinful will against another:
Your desire will be for your husband,
and he will rule over you. (Gen. 3:16)
This means all marriages are hard. But in a Christian marriage, spouses have the opportunity to call one another to submit one’s sinful wills to God’s perfect will. When you marry a non-Christian, you lose out on the blessing of having a spouse who calls you to submit your will to Christ, and instead have a spouse who has no interest in being called to submit their own will to Christ.
4) The Old Testament warns against marrying unbelievers.
In the rest of Genesis, we see a huge effort made to ensure the people of God would only marry those who trust the Lord.
In Genesis 24, we see the great lengths Abraham goes to—combined with God’s amazing answer to prayer—to ensure that his son Isaac marries believing Rebekah.
In Genesis 27:46–28:9, we see Rebekah and Isaac’s disgust at the marriage of her son to Canaanite/Hittite women. This isn’t racism: It’s religious.
In Genesis 34:8–9, Hamor invites the sons of Jacob to intermarry with the daughters of Shechem (a town that has just proved its character in the mistreatment of Dinah). To intermarry with this town rather than distance themselves from such defilement would have been the ultimate compromise; it would have destroyed the people of God in the first generation.
In the conquest of Canaan, the Lord gives strict prohibitions against intermarriage:
Do not intermarry with them. Do not give your daughters to their sons or take their daughters for your sons, for they will turn your children away from following me to serve other gods, and the Lord’s anger will burn against you and will quickly destroy you. (Deut. 7:3–4)
This prohibition is repeated in Joshua 23:12, and the trajectory of intermarriage never assumes or expects the Canaanites would end up being converted.
Intermarriage is also the downfall of kings: even the super-wise Solomon (1 Kings 11) and most obviously Ahab (1 Kings 16–19). More positively, a sign of repentance for God’s people was their repentance of intermarriage in Ezra 9–10. On the other hand, if a foreigner was already converted, then there was absolutely no prohibition against marrying them. In fact, this is seen as a positive (Zipporah, Rahab, Ruth).
All this biblical evidence makes me think that “I’ll keep following Jesus even with an unbelieving spouse” is a very proud statement that underestimates our own weakness, and presumes upon God’s grace.
