Some excerpts from Charles Fillmore's writings on Genesis 1

Charles Fillmore’s teaching about the six days of creation:

The six-day creation of the universe (including man) as described in Genesis is a symbolic story of the work of the higher realms of the mind under divine law. (Atom-smashing Power of the Mind, p. 12)

Read in the light of Spirit, the first chapter of Genesis is a description, in symbol, of the creative action of universal Mind in the realm of ideas.
It does not pertain to the manifest universe any more than the history of the inventor’s idea pertains to the machine that he builds to manifest the idea. First the problem is thought out, and afterwards the structure is produced. So God builds his universe. (Christian Healing, pages 31-32.)

Divine Mind first images the idea, then perceives his fulfillment. Man, acting in cooperation with
Divine Mind, places himself under the same creative law and thus brings his ideas into manifestation. (Mysteries of Genesis, pages 20-21)

It is found that what is true in the creation of the universe (as allegorically stated in Genesis) is equally true in the unfoldment of man’s mind and body, because man is a microcosmic copy of the “Grand Man” of the universe. (Mysteries of Genesis, page 10)

[The following are all excerpts from Chapter One of Mysteries of Genesis]

The first step in creation is the awakening of man to spiritual consciousness, the dawning of light in his mind, his perception of Truth through the quickening of his spirit... the first day’s work is the calling of light or wisdom into expression.

The second step in creation is the development of faith or the “firmament.”

The third step in creation is the beginning of the formative activity of the mind called imagination. This gathers “the waters... together unto one place” so that the “dry land” appears. The first today’s creation reveals the light or inspiration of Spirit. The second day establishes faith in our possibilities to bring forth the invisible. The third day’s creation or third movement of Divine Mind pictures the activity of ideas in mind. This is called expression.

The fourth step in creation is the development of the “two great lights” the will and the understanding, or the sun (the spiritual I AM) and the moon (intellect). These are but reflectors of the true light; for God had said, “Let there be light: and there was light” -- before the sun and the moon were created.

The fifth step in creation is the bringing forth of sensation and discrimination. The “creatures” are thoughts. The “birds” are ideas approaching spiritual understanding. In the fifth day’s creation ideas of discrimination and judgment are developed. Another orderly degree of mind unfoldment is fulfilled. Another step in spiritual growth is worked out in consciousness when the individual enters into the quickening of his judgment and seeks to conform his ideas to those of Divine Mind.

The six step in creation is the bringing forth of ideas after their kind. When man approaches a creative level in his thought, he is getting close to God in his consciousness, and then the realization that he is the very image and likeness of his Creator dawns on him. This is the consciousness in man of Christ.

The creation described in these six days or six “steps” or stages of God-Mind is wholly spiritual and should not be confounded with the manifestation that is described in the succeeding chapters. God is mind, and all His works are created in mind as perfect ideas.

[End of quotations]

Summing up, Unity Institute course material on "The Creative Process" sums up the six days of creation like this:

God created the universe in stages or steps, not entirely separate from one another but rather each one building on and adding to the one before. God's creative steps were:

1. Light

2. Dome or firmament

3. Waters, dry lands, vegetation

4. Lights in the dome

5. Birds and fish

6. Creatures of the earth

7. Sabbath; God rested

Metaphysically, we must also work in orderly steps, adding each new step to the foundation laid by the one before. The steps of the Creative Process are:
1. Light
2. Faith
3. Imagination
4. Will/Understanding
5. Judgment
6. Love
7. Sabbath