The Book of First Kings 4:32 says that Solomon wrote 1005 songs. A song is poetry like the Psalms that were sung to bring forth a message from God. God deemed this song important enough to keep it in His manual, the Bible. The Books of First and Second Samuel are the historical books of David, but His love and emotions for God were written in his Psalms. Likewise, the Book of Revelation is a historical book of the bride of Christ, but the Song of Solomon is the love and emotions of Christ and His bride. This book is being published at the same time as Revelation to be companion books with the same overview. God desired a people who would be adopted into His kingdom. Christ would redeem every person who would acknowledge the plan of God to become children of the Most High God. The Bible was inspired by God (2 Tim 3:16).
The Book of Song of Solomon shows the love of the Lord Jesus to His bride, the Church, who is called Shulamite. Shulamite in Hebrew is the feminine noun for Solomon. Solomon in Hebrew is shalom meaning peace unto wholeness. This wholeness comes from a relationship with the Lord which is offered to everyone, male or female, Jewish or Gentile (non-Jewish). Do not think of Solomon in this book as the king, for he too is a believer in the Lord, so therefore He too can be the Shulamite. This is not a picture of Solomon's love for a woman, but instead the story of how Solomon came to love the Lord and grow spiritually throughout His life. Both Books (Revelation and Song of Solomon) are actually a symbolic picture of the Ancient Jewish Wedding. The bride is the Church, and therefore, seen as female, yet we know that God is identified as being present in both male and female. Therefore, Solomon is writing as a believer growing in his walk with the Lord.
Song of Solomon, like all books in the Old Testament, point to Jesus. It can't be about Solomon and his love for a woman; IT HAS TO BE ABOUT JESUS. Therefore, it shows how a believer grows in their relationship with Jesus. The Jewish wedding takes us from the first time we see Jesus in the spirit and are engaged (salvation) to the time we see Jesus face to face in marriage (our resurrection) to the time we return with Christ to rule and reign as His wife (Millennium) to the time we live in the new heaven and earth (eternity). The intention of this book is to experience in the spirit the life of the believer growing in our knowledge and relationship with Jesus Christ.