The second metaphor for the believer’s relationship with God is marriage. St. Paul exhorted the believers: “Therefore, my brethren, you also have become dead to the law through the body of Christ, that you may be married to another—to Him who was raised from the dead, that we should bear fruit to God.” (Romans 7:4)
The dominant image of the Gospels regarding our marriage to Christ is, of course, that of the wise and foolish virgins: those of us who prepare ourselves for the coming of the Bridegroom will be joined with Him in marriage. The parable of the virgins connects to the Church being the Bride of Christ.
The image of adoption highlights God’s action – that of promoting us, as it were, from slaves to heirs. Though it is still Christ who takes us to be His Bride, the image of marriage highlights the things we can do in preparation. We must practice fidelity, wisdom, and singleness of purpose; we must not be distracted by the foolish things of the flesh from our preparation for the wedding feast. If adoption emphasizes the freedom we acquire in the Father’s love, marriage emphasizes the obedience and fruitfulness which is proper to a spouse, and particularly to a wife.
Note that the metaphor of marriage implies a very different relationship with family of origin than the metaphor of adoption. A bride is not a former slave, separated from her family, but is taken from among one’s equals. And, at least in the ideal, she does not become a bride without her family’s blessing; she does not escape to her groom but is brought to him joyfully by those who love her.
Unlike adoption, which, as discussed before, appears primarily in the context of the Gentiles’ incorporation into Israel, the metaphor of marriage is much beloved by the Jewish people. For instance, the traditional Jewish interpretation of the Song of Songs is that of a courtship and marriage between God and His people Israel; the text, seen in that light, is frequently used in worship. There is a continuity between Jewish and Christian use of the language of marriage to describe the way in which God desires us to relate to Him. This, to me, suggests once again that marriage is the metaphor Jewish Christians can use most fruitfully to talk to other Jews about their conversion.
However, there is a significant difference between the Jewish and the Christian view of our marriage to God. For believing Jews, the marriage is corporate: the bride is all of Israel. For Christians, it is both corporate and individual: the Church as a whole, like Israel, is the Bride of Christ, but each individual believer, too, is one of the virgins who waits for the Bridegroom.
The question from the Jewish perspective, then, is whether a Jew can “claim” marriage into Christ in separation from his people. This is where the adoption metaphor comes in: though the convert Jew may be exiled from his family of origin (usually through the family’s, rather than the convert’s, doing – more on that later), he is united with those who have been adopted into the family – that is, with the New Israel.