Question: If the Torah can’t be taken literally because it talks about the spiritual world, how can we understand what is written there?
Answer: Baal HaSulam explains in the Introduction to The Study of Ten Sefirot that the entire Torah is divided into PARDESS : Pshat (simple explanation), Remez (hint), Drush (allegory), and Sod (secret).
And as the Vilna Gaon explains study of the Torah begins from the secret, and not from the simple explanation. It means that it is attained in this order: Sod (secret), Drush (allegory), Remez (hint), and only at the very end Pshat (simple explanation).
When we begin to read the Torah we understand nothing in it and think that this is some kind of fairy tale or historical novel and nothing more. And therefore it is a secret to us.
And only later, through the study of Kabbalah, do we penetrate deeper into the Torah text and begin to understand what it says about the internal world, the forces of our soul, and the forces that control us. And then the Torah is transformed first into an allegory, then into a hint, and in the end, it becomes simple and easy to understand for us.
Israeli Radio Program 103FM, 2/28/16