G‑d talks to us in many voices: benevolent, authoritative, wrathful, romantic. Romantic? Just read Isaiah 54, or Song of Songs. Or listen to Him reminisce on our honeymoon: "I remember the kindness of your youth, your bridal love, following after me in the desert, in an unsown land..." (Jeremiah 2:1).

And like a jealous lover, He insists that ours be a monogamous relationship. Indeed, our sages regard the Seventh Commandment, "You shall not commit adultery" as the extension and mirror-image of the Second Commandment, "You shall have no other gods before Me." (According to the Midrash, the first five Commandments correspond to the second five — see here.) We're married to each other, G‑d is saying; the loyalty I expect from you is no less than that which you expect from your spouse.

Conversely, G‑d is also saying: human love is divine. Love between a man and a woman will attain its most glorious heights and richest depths only when it is true to its divine essence — when their place in each other's hearts and lives is as unequivocal as the Creator's place in His creation. When they can no more betray each other than a man can betray his G‑d.