Far from comprehensive, here are some brief thoughts on the main purpose of the biblical book, Song of Solomon:
Song of Solomon is a lyrical poem praising the virtues of love between a man and a woman. The book is a love song that takes the form of a dialogue between a woman and a man with complimenting choruses from her friends, often presented as the “Young Women of Jerusalem.”
I disagree with the oft proposed notion that it is a linear progression of a man and woman from courtship through marriage. Nor do I believe it to be love confined within our modern Christian ideal of marriage. Rather, I would argue that Song of Solomon belongs to the category of Hebrew wisdom literature, and as such, was written to teach about the beauty and purity of human sexuality. It also extols the virtues of monogamy. The teachings of this book could be seen as a response to David’s sexual sin and Solomon’s idolatry.