“Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” (Ephesians 5:31)
The first purpose of marriage is loving companionship—the unity of two in a relationship mirroring the nature of God himself (see Eph. 5:22-23). One way to violate this unity from the outset is to marry an unbeliever. Marriage to an unbeliever reveals a very low view of marriage, of one’s relationship to God, or of both. For unity to be complete, oneness in spirit is the prime requisite. If the most important relationship in life is with God, how can a couple have unity at any real depth when one is with God and the other is not?
Not only does marriage to an unbeliever diminish the potential for fulfilling the first purpose in marriage, it also puts in great jeopardy the second purpose—having children in a God-fearing home environment. Finally, it completely rules out the third purpose of demonstrating the relationship God desires with his people. If the believing partner gives up his relationship with the Lord, some measure of unity can be built on a godless foundation as if both were unbelievers. But unless the unbeliever comes to Christ, no Christian marriage can be achieved, and no oneness at the deepest levels can be experienced.
At any rate, the Bible expressly prohibits such a union. Of course, one who is married to an unbeliever should remain married (1 Cor. 7:12-13). Though union will be limited, it is better than divorce, according to Paul.
How should others relate to a Christian who is planning marriage to an unbeliever, besides prayer against the consummation of the plan, and biblical counsel? Any minister of the gospel who officiates at a marriage between a believer and an unbeliever participates in the sin. Having said this, however, it should be emphasized that Christian people and pastors need so to relate to the Christian who is bent on unbiblical marriage that a trusting relationship is maintained even if the advice is rejected. Because the continuance of the marriage becomes the will of God once it has been consummated, it is important for Christian people to help the Christian partner come to repentance for disobeying God, and to assist in building as true a unity as possible in the mixed marriage.
“What is the root cause of disunity?” you might ask. Stress and conflict in marriage are said to damage seriously 60 to 90 percent of Christian marriages. Seminars, books, and counselors devoted to treating this epidemic increase geometrically, but the infection seems to spread and deepen. The vast majority of these “combat zones” do not really need sexual or psychological adjustment. Often the cures advocated simply apply Band-Aids to cancers and drive the true illness deeper inside. The root problem in most cases is old-fashioned sinful selfishness. “Lack of maturity is at the bottom of 90 percent of all marital problems,” said widely read counselor Norman Vincent Peale. Unity is impossible without self-giving as a way of life on the part of both mates. If one or both insist on personal rights and personal fulfillment rather than personal self-sacrifice in love for the other, true and lasting unity is impossible.
Whether married or not, we can pray for marriages around us. For love for the other that if needed, one sacrifices personal rights for the well-being of the family. We pray for ourselves that self-giving marks our relationships. Pray there is companionship and unity, demonstrating the relationship God desires with his people. Love…..Unity….Sacrifice….Pleasure….Oneness with God and with one another.
 Deut. 7:3-4; Neh. 13:23-27; 1 Cor. 7:39; 2 Cor. 6:14-18
 Norman Vincent Peale, “Man, Morals, Maturity,” Readers Digest, November 1965,184.
 Introduction to Biblical Ethics (IBE), Robertson McQuilkin, (2014), 234-235.