Who is the Goddess? 

(By unkown)

And the Child asked the Maiden: Who is the Goddess?

The Maiden turned and replied: the Goddess is Pure. She is the first
burst of Life. She is untouched by Man. She is One who finds Joy in
everything. She is a Sister. She is a Child. She is One who is
Servant to None for She has no Consort and no Child. She is the
Huntress. She is Innocence. She is Growth.
But the Child was unsatisfied.

And the Child asked the Mother: Who is the Goddess?

The Mother turned and replied: The Goddess is She who nurtures us.
She keeps us safe. She guides us. She is the One to whom we can
turn. She is the mother with the child at the breast. She is the
pregnant woman. She is the One who has the earth as her body, the
full moon as her symbol. She is the One on whom we depend for life.
She sustains us. She is Life.
Still the child was unsatisfied. 

And the Child asked the Crone: Who is the Goddess?

The Crone turned and replied: She is Death and Rebirth. She is the
Wisdom Collected over many Lives. She is All that has Happened. She
is All that will Happen. She is One who has come to the end of the
Cycle. She is Feared by the Young. She is the welcome Aid to those
in Pain, to those who suffer. She is the One to whom All turn when
They no longer wish for the Life She has given Them. She is
Destruction in preparation for the New. Still the Child was unsatisfied. The Child looked around but there was no one else to ask. 

Finally the Child shouted: GODDESS! GODDESS, WHO ARE YOU?

The Goddess replied: I am the maiden. I am the mother. I am the
Crone. I am Diana. I am Isis. I am Kali. I am Birth. I am Life. I am Death. I am Creation. I Sustain. I am the Destroyer. I am one
Goddess. I am Thousands of Separate Goddesses. I am in Everything. I am Everywhere. I am Eternal. I am in Everyone. I am whoever You want me to be. I am in You.

And the Child was satisfied.

The Triple Goddess

The Goddess is the womb from which life sprung. She is the Universal Mother. She is both life and death. The earth is her body. We see her in three aspects, all associated with the stages of a women's life and the phases of the moon as it moves through it's cycle like women who have a menstrual cycle.

The waxing moon is the Maiden aspect. This is when the Goddess is young, adventurous, high spirited, fresh, full of ideas and initiative. She is seen in the blooms of spring.

The full moon is the Mother aspect. She now represents bounty, fulfillment and most of all balance. She is the bringer of knowledge and loving caresses.

The waning moon is the time of the Crone. She is the guardian of secrets unknown ands the bringer of wisdom. She is also the more feared of the three aspects as she is often known as the Goddess of Death and the bringer of destruction. But we must remember that out of death and destruction comes life. When a fire burns in the forest, the trees may fall, but it creates room for new trees to grow. 

In Wicca. A Guide for the solitary practitioner - Scott Cunningham wrote:  

"She is the unploughed field, the full harvest, and the dormant, frost-covered earth. She gives birth to abundance. But as life is her gift, she lends it with the promise of death. This is not darkness and oblivion, but rest from the toils of physical existence. It is human existence between incarnations.
Since the Goddess is nature, all nature, she is both the temptress and the crone; the tornado and the fresh spring rain; the cradle and the grave.
But though she is possessed of both natures, the Wicca revere to her as the giver of fertility, love, and abundance, though they acknowledge her darker side as well. We see her in the moon, the soundless, ever-moving sea, and in the green growth of the first spring. She is the embodiment of fertility and love."