Many a young Christian has ruined his life because of unholy alliance in marriage. Marriage is a yoke. The Bible forbids unequal yoke (2 Cor 6:14). "You shall not plow with an ox and a donkey together" (Dt 22:10). Reading: 2 Corinthians 6:11-18 "Do not be unequally yoked together with unbelievers" (2 Cor 6:14)
Both the Old and the New Testaments strongly condemn intermarriage with unbelievers. Intermingling the "holy seed" with the unconverted is called as "trespass, transgression, iniquity and guilt" (Ezra 9:1-6). Even a widow who is a believer is not permitted to marry an unbeliever. "She is at liberty to be married to whom she wishes, only in the Lord" (1 Cor 7:39).
Even if your parents press you to marry an unbeliever, for whatever reason, you can firmly refuse. Obedience to parents also must be "in the Lord" (Eph 6:1). If you have fallen in love with an unbeliever, break the affair unless your fiance or fiancee gets genuinely converted. Beware of baptisms just for the sake of marriage!
True in some cases the unbelieving spouse gets converted after marriage. But no truth can be established from this. The Bible challenges, "How do you know, O wife, whether you will save your husband? Or how do you know, O husband, whether you will save your wife?" (1 Cor 7:16). Marriage is too serious a matter to take risk. If you have already made the mistake of marrying an unbeliever, you can now do nothing but pray and believe God for his or her salvation.
When young people from non-Christian background embrace the Gospel, they find it extremely difficult to find suitable believing partners. Casteism is prevalent even among Christians in India. Christian leaders and pastors must voluntarily take sincere efforts to settle marriages for the non-Christian converts. Believing young people from Christian families should come forward to marry non-Christian converts. Why not? Sometimes the families of these converts may throw them out of their community. The Church should support such with all sensitivity.
Thy way, not mine, O Lord, however dark it be;
Lead me by Thine own hand, choose Thou the path for me.
I dare not choose my lot; I would not if might;
Choose Thou for me, my God, so shall I walk aright!Stanley On Bible