Symbolism is perhaps the most noticeable literary feature of "The Golden Key."

The symbols often embody layers of meaning, such as the golden key, which may stand for the imaginative faculty, or steadfast faith and love, or the inquisitive mind, or the willingness to follow leaders. Any or all of these could be "keys" which help people unlock the mysteries of life. The dominant symbol in the book is that of the journey or quest. As Mossy and Tangle seek the land at the top of the rainbow, they overcome physical obstacles that represent hindrances to their spiritual growth. The outer journey reflects their interior progress.

Other symbols in the work—the rainbow, fire, water, doorways, light and darkness—are all controlled by the central importance of the quest.