There are two primary reasons why God forbids the joining of a believer to an unbeliever. One is that Christians have been reborn; they are spiritually alive, whereas unbelievers are not. A person who has not received Jesus Christ as personal Savior is spiritually dead!
I shall never forget the time I heard a pastor explain that any regenerated sinner who joins with one who is not, is like Doctor Frankenstein: creating a monster over which he eventually will lose control.
When a woman who is alive in Christ disobediently binds herself to an unbeliever, it is the same as amputating a leg from a corpse, then surgically attaching that dead, decaying appendage to her living body. The leg will never regenerate. Instead, it will cause infection and spread disease and poison throughout her entire being. And, she will have to live with the consequences of that action for the rest of her physical life.
The main reason God is against unequal yoking is that it is an affront to His holiness. God is separate and set apart from all that is sinful and evil. Those who belong to Him are to emulate His purity. God has commanded, “You shall be holy for I am holy” (Lev. 11:45).
Intermarriage reduces the purity factor in the life of the believer and adulterates the divine institution of marriage, which should be a reflection of the Christ-church relationship. Although, in His grace, God does not look upon the Christian wife or the children as defiled or impure, He must turn His back on the unbelieving mate, who abides in a permanent state of evil rather than in Him.
God cannot commune with the unsaved mate. Positionally he is unholy— unrighteous —because he has not been redeemed, so his sin is a barrier that walls him off from the presence and grace of God.
Not only is the purposeful joining of the believer to an unbeliever an affront to God’s holiness, but the lifestyle of someone who is not a Christian also offends the Lord. During the time of the prophet Ezra the children of Israel had married outside of the faith. God’s reaction was so pronounced that He demanded that every unbelieving mate be banished from the nation Israel.
Why did God react so strongly to this intermarriage? Ezra says it was because the unbelievers committed abominations against the Lord. What were the abominations? Worship of false gods and of idols, and participation in all of the paganism that was involved in the accompanying rituals.
If you trace what happens to God’s children when they get involved with unbelievers, you will find drunkenness, murder, rape, incest, adultery, and desecration of the true worship procedures God has instituted. Reflect on David; what happened when he pursued Bathsheba?
You may recall that Solomon, who Scripture says is the wisest man who ever lived, foolishly brought heathen wives into the temple. This act almost destroyed him. He didn’t do this when he was young and impetuous. He committed this sin when he was an old man. In his twilight years he was a broken man; depressed, despondent, and guilt-ridden, because he disobeyed God’s law about intermarriage.
… God’s direct command in 2 Corinthians 6:14-15 says, “Do not be bound together with unbelievers; for what partnership have righteousness and lawlessness, or what fellowship has light with darkness? Or what harmony has Christ with Belial, or what has a believer in common with an unbeliever? Or what agreement has the temple of God with idols? For we are the temple of the living God.“
These verses consist of two parts. The first is the command to not be unequally yoked. Obviously, it is addressed to Christians. The second part deals with the rationale behind why it is sinful, even unthinkable, for a believer who belongs to God and is indwelt by the Holy Spirit, to link up with someone who belongs to Satan and is under his dominion.
To emphasize the impossibility of a believer uniting in a permanent relationship with an unbeliever, Paul asks several rhetorical questions. One is, “What partnership have righteousness and lawlessness?” He is referring to the fact of the believer’s position in Christ. When we receive Christ we made righteous in God’s eyes. He accepts us because we are clothed in Christ’s righteousness. It is, therefore, inconceivable that one who is in a position of perfection would attach herself to one who is totally sinful.
He also asks what fellowship light has with darkness. The Greek word for fellowship is koinonia. It implies an intimate relationship, a communion of souls. John tells us that “God is light, and in Him there is no darkness at all” (1 John 1:5). We are ordained to walk in the light and have fellowship with the Lord. If we unite with someone who is not walking in God’s light, we are blocking His illumination in our lives, melding with the darkness of sin and choosing to live in the shadow of evil.
The next comparison is potent. Paul asks how Christ and the devil can have harmony. Obviously, they can’t. When a believer marries an unbeliever, disharmony is a natural result. The disobedient Christian is intentionally joining a child of God to a child of Satan, forming an unholy alliance with the evil one, when in reality a Christian has already pledged herself to a holy union with the living God.
This article comes from the terrific book, Beloved Unbeliever: Loving Your Husband into the Faith, written by Jo Berry, published by Zondervan Publishing. This book could truly help those who are married to unbelieving spouses. And it can also help those who are contemplating marrying someone who isn’t a believer, as you can see from the above material.