“The basic principle here is truly clear: Christians may not enter into spiritual relations with pagans. As Calvin notes in his commentary on this passage, Paul is not here addressing marriage. He is addressing the problem of syncretism, of attempting to synthesize Christianity with idolatry.”
One of the great temptations faced by the Israelites as the entered the land of Canaan would be to absorb the Canaanite religion and thereby either to apostatize by becoming pagans or to attempt to synthesize Canaanite paganism with the biblical religion. Yahweh explicitly commanded that, after the entered Canaan, they shall not inter-marry with them:
Furthermore, you shall not intermarry with them; you shall not give your daughters to their sons, nor shall you take their daughters for your sons. For they will turn your sons away from following me to serve other gods; then the anger of Yahweh will be kindled against you and He will quickly destroy you (Deut 7:3–4).
The command is not an expression of bigotry. The commandment is an application of the moral law: you shall love Yahweh your God with all your heart, soul, mind, and strength and your neighbor as yourself” (Matt 22:37–40). The pagan gods, idols, are not (1 Cor 8:4–6). The fictitious gods of the Canaanites did not deliver the Israelites from Pharaoh and Egypt. Yahweh did. The Canaanite gods did not speak into nothing (because they are nothing) and make all that is (Gen 1), Yahweh did. The Canaanite gods are lies. Yahweh is the truth. To inter-marry with the Canaanites and then to adopt their gods would be apostasy and idolatry, both strictly forbidden by the first two commandments. It would also be cruelty to the Canaanites, to pretend that their gods are real. It would be a violation of the 9th commandment, i.e., a lie and it would only encourage the Canaanites to continue to worship false gods when they should turn, in repentance and faith, to Yahweh as Rahab did (Heb 11:31). Further, such a marriage puts the believer in spiritual jeopardy as it may lead them away from Yahweh.
Yahweh’s commands to his national people are so clear, so explicit that there can be no genuine question about the intent. Does that intent still bind Christians today or has the advent of the New Covenant so changed things that Christians are free to inter-marry with pagans today?
The first challenge is that in Paul’s instructions to the Corinthians on marriage in 1 Corinthians 7 he does not address the question directly. What was before him there was the question of the status of a marriage once one of the parties had been converted to Christianity. Should the believer remain married or should the believer seek a divorce? Paul says:
But to the rest I say, not the Lord, that if any brother has a wife who is an unbeliever, and she consents to live with him, he must not divorce her. And a woman who has an unbelieving husband, and he consents to live with her, she must not send her husband away. For the unbelieving husband is sanctified through his wife, and the unbelieving wife is sanctified through her believing husband; for otherwise your children are unclean, but now they are holy. Yet if the unbelieving one leaves, let him leave; the brother or the sister is not under bondage in such cases, but God has called us to peace. For 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 7:12–16; NASB 1995).
This fits Paul’s general theme in this section, that the believer should remain in the state they were when they came to faith. He nowhere says, implies, or even suggests that believers should contract a marriage with an unbeliever. It is one thing to find one’s self, upon being given new life (i.e., upon being regenerated by the Spirit) to be married to an unbeliever. It is quite another thing for a believer to enter into a marriage with an unbeliever. Paul says that the believer who now finds himself (or herself) married to an unbeliever should remain married, if the unbeliever will permit, in part because the Lord may use this anomalous situation to bring the unbeliever to new life and to true faith. He does not say that the unbeliever is now presently saved by virtue of being married to a believer. He does does that the believer, in this circumstance, is not defiled by virtue of being married to an unbeliever. Hence his use of Levitical language of “sanctified” (ἡγίασται) and “holy” (ἅγιά) in the context of being “clean” and “unclean” (ἀκάθαρτά). See Leviticus 7:19; 10:10; 11:32, 36, 47; 13:59 etc. Paul is invoking the category and language of ceremonial defilement. One of the questions the Corinthians are asking is whether, after coming to faith, they are made ceremonially or religiously unclean or defiled by now being married to an unbeliever.
Whether a Christian should enter into a marriage with an unbeliever is another question. It does not seem that the Corinthians asked Paul about this specifically or if they did we have no record of it. Given the question he addressed in 1 Corinthians 7, given that they were worried about remaining in a marriage with an unbeliever, it would seem that they assumed that it would be immoral to enter into a marriage with an unbeliever.
Given the clear teaching in Deuteronomy 7 the principle would seem to be clear. To be sure, we must be cautious in the way we apply commandments applied for the Israelites. E.g., we know that the food prohibitions have been fulfilled and repealed (Acts 10:10–16). Nevertheless, we understand that there are certain basic principles from the Torah that are permanent. The ceremonies and sacrifices have fulfilled their purpose.
The principle of not marrying pagans is not a ceremony but a basic principle. In 2 Corinthians 6:14–7:1 Paul writes:
Do not be yoked together with unbelievers; for what partnership has righteousness and lawlessness, or what fellowship has light with darkness? Or what agreement has Christ with Belial, or what part has a believer in with an unbeliever? Or what agreement has the temple of God with the temple of idols? For we are the temple of the living God; just as God said, ‘I will dwell in them and walk among them; and I will be their God, and they shall be my people.’ Therefore ‘come out from their midst and be separate,’ says the Lord ‘and do not touch what is unclean’ and I will welcome you. ‘And I will be father to you, and you shall be sons and daughters to me,’ says the Lord almighty. Therefore, having these promises, beloved, let us cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God.
The basic principle here is truly clear: Christians may not enter into spiritual relations with pagans. As Calvin notes in his commentary on this passage, Paul is not here addressing marriage. He is addressing the problem of syncretism, of attempting to synthesize Christianity with idolatry. As in 1 Corinthians 10, he is calling them to recognize the profound spiritual gulf between belief and unbelief. When Christians are invited to participate in a pagan religious feast, we must graciously decline. We have been bought with a price. We are not our own. We are wholly owned subsidiaries of Christ, citizens of his kingdom.
Nevertheless, this passage certainly has application to the question of marriage. Few relationships are as intimate and personal as marriage. To be married is to be yoked. In marriage, our Lord says, “the two shall become one flesh” (Gen 2:23; Mark 10:8). For the Christian, marriage is a mystery. Paul says that a Christian marriage is a picture of the relationship between Christ and his church (Eph 5:28–33). That is not true when a Christian marries a non-Christian. Such a marriage deforms the analogy, the mystery of which Paul speaks. There is an analogy for this. In 1 Corinthians 6, Paul says that the Christian is united to Christ. Should a Christian have sex with a prostitute, he would be (were it possible) joining Christ to a prostitute (1 Cor 6:14–19). To reinforce that point, he makes the same argument in the following verses that he makes here in 2 Corinthians 6 and 7, that believers are the temple of God and unbelievers are the temple of another spiritual entity.