The Prophets, particularly Hosea and Ezekiel, described God's passion for his people using boldly erotic images. God's relationship with Israel is described using the metaphors of betrothal and marriage; idolatry is thus adultery and prostitution. Here we find a specific reference—as we have seen—to the fertility cults and their abuse of eros, but also a description of the relationship of fidelity between Israel and her God. The history of the love-relationship between God and Israel consists, at the deepest level, in the fact that he gives her the Torah, thereby opening Israel's eyes to man's true nature and showing her the path leading to true humanism. It consists in the fact that man, through a life of fidelity to the one God, comes to experience himself as loved by God, and discovers joy in truth and in righteousness—a joy in God which becomes his essential happiness: “Whom do I have in heaven but you? And there is nothing upon earth that I desire besides you ... for me it is good to be near God” (Ps 73 :25, 28).
10. We have seen that God's eros for man is also totally agape. This is not only because it is bestowed in a completely gratuitous manner, without any previous merit, but also because it is love which forgives. Hosea above all shows us that this agape dimension of God's love for man goes far beyond the aspect of gratuity. Israel has committed “adultery” and has broken the covenant; God should judge and repudiate her. It is precisely at this point that God is revealed to be God and not man: “How can I give you up, O Ephraim! How can I hand you over, O Israel! ... My heart recoils within me, my compassion grows warm and tender. I will not execute my fierce anger, I will not again destroy Ephraim; for I am God and not man, the Holy One in your midst” (Hos 11:8-9). God's passionate love for his people—for humanity—is at the same time a forgiving love. It is so great that it turns God against himself, his love against his justice. Here Christians can see a dim prefigurement of the mystery of the Cross: so great is God's love for man that by becoming man he follows him even into death, and so reconciles justice and love.
The philosophical dimension to be noted in this biblical vision, and its importance from the standpoint of the history of religions, lies in the fact that on the one hand we find ourselves before a strictly metaphysical image of God: God is the absolute and ultimate source of all being; but this universal principle of creation—the Logos, primordial reason—is at the same time a lover with all the passion of a true love. Eros is thus supremely ennobled, yet at the same time it is so purified as to become one with agape. We can thus see how the reception of the Song of Songs in the canon of sacred Scripture was soon explained by the idea that these love songs ultimately describe God's relation to man and man's relation to God. Thus the Song of Songs became, both in Christian and Jewish literature, a source of mystical knowledge and experience, an expression of the essence of biblical faith: that man can indeed enter into union with God—his primordial aspiration. But this union is no mere fusion, a sinking in the nameless ocean of the Divine; it is a unity which creates love, a unity in which both God and man remain themselves and yet become fully one. As Saint Paul says: “He who is united to the Lord becomes one spirit with him” (1 Cor 6:17).
11. The first novelty of biblical faith consists, as we have seen, in its image of God. The second, essentially connected to this, is found in the image of man. The biblical account of creation speaks of the solitude of Adam, the first man, and God's decision to give him a helper. Of all other creatures, not one is capable of being the helper that man needs, even though he has assigned a name to all the wild beasts and birds and thus made them fully a part of his life. So God forms woman from the rib of man. Now Adam finds the helper that he needed: “This at last is bone of my bones and flesh of my flesh” (Gen 2:23). Here one might detect hints of ideas that are also found, for example, in the myth mentioned by Plato, according to which man was originally spherical, because he was complete in himself and self-sufficient. But as a punishment for pride, he was split in two by Zeus, so that now he longs for his other half, striving with all his being to possess it and thus regain his integrity. While the biblical narrative does not speak of punishment, the idea is certainly present that man is somehow incomplete, driven by nature to seek in another the part that can make him whole, the idea that only in communion with the opposite sex can he become “complete”. The biblical account thus concludes with a prophecy about Adam: “Therefore a man leaves his father and his mother and cleaves to his wife and they become one flesh” (Gen 2:24).
Two aspects of this are important. First, eros is somehow rooted in man's very nature; Adam is a seeker, who “abandons his mother and father” in order to find woman; only together do the two represent complete humanity and become “one flesh”. The second aspect is equally important. From the standpoint of creation, eros directs man towards marriage, to a bond which is unique and definitive; thus, and only thus, does it fulfil its deepest purpose. Corresponding to the image of a monotheistic God is monogamous marriage. Marriage based on exclusive and definitive love becomes the icon of the relationship between God and his people and vice versa. God's way of loving becomes the measure of human love. This close connection between eros and marriage in the Bible has practically no equivalent in extra-biblical literature.