Who is Shakti?..... Allow her to answer for Herself....

I am Manifest, Unmanifest and Transcendent Divinity,
I am Brahma, Vishnu and Shiva
As well as Saraswati, Laksmi and Parvati
I am the Earth, The Sun and the Stars
And I am the also the Moon
I am all animal and birds,
And I am the outcast as well, and the thief
I am the low person of dreadful deeds,
And the great person of excellent deeds
I am Female. I am Male and I am Neuter

In the Deviís Supreme Cosmic Form,
The Satyaloka is situated on the topmost of Her head;
The Sun and Moon are her eyes;
The quarters of the sky are Her ears;
The Vedas are Her words;
The Universe is Her heart;
The Earth is Her loins;
The space between earth and sky is Her navel;
The constellations are Her Thighs;
The Maharaloka is Her neck;
The Janarloka is Her face;
Indra and the Devas of the Svarloka are her arms;
Sound is the organ of Her ears;
Fire is within her Face;
Day and Night are Her wings;
The mountains are Her bones;
The rivers are Her veins,
And the trees are the hairs of Her body.
Childhood, youth, and old age are Her finest modes;
The two twilights are Her raiment;
And the Moon is the mind of the Mother of the Universe.
~ Devi Bhagavata Purana, VII.33.1-21

I travel with the Rudras and the Vasus, with the Adityas and All-Gods I wander. I hold aloft both Varuna and Mitra, Indra and Agni, and the Pair of Asvins.

I cherish and sustain high-swelling Soma, and Tvastar I support, Pusan, and Bhaga. I load with wealth the zealous sacrificer who pours the juice and offers his oblation

I am the Queen, the gatherer-up of treasures, most thoughtful, first of those who merit worship. Thus Gods have stablished me in many places with many homes to enter and abide in.

Through me alone all eat the food that feeds them,-each man who sees, brewhes, hears the word outspoken. They know it not, but yet they dwell beside me. Hear, one and all, the truth as I declare it.

I, verily, myself announce and utter the word that Gods and men alike shall welcome. I make the man I love exceeding mighty, make him a sage, a Rsi, and a Brahman.

I bend the bow for Rudra that his arrow may strike and slay the hater of devotion. I rouse and order battle for the people, and I have penetrated Earth and Heaven.

On the world's summit I bring forth the Father: my home is in the waters, in the ocean. Thence I extend o'er all existing creatures, and touch even yonder heaven with my forehead.
I breathe a strong breath like the wind and tempest, the while I hold together all existence. Beyond this wide earth and beyond the heavens I have become so mighty in my grandeur.

Devi suktha-Rigveda, mandala 1,suktha 125

Let my every word be a prayer to Thee,
Every movement of my hands a ritual gesture to Thee,
Every step I take a circumambulation of Thy image,
Every morsel I eat a rite of sacrifice to Thee,
Every time I lay down a prostration at Thy feet;
Every act of personal pleasure and all else that I do,
Let it all be a form of worshiping Thee."
From Verse 27 of Shri Aadi Shankara's Saundaryalahari

So, the creation that you are about to perform, know Shakti to be the cause thereof. When you will be endowed with that Shakti, you will be able to create the world. Vishnu, Shiva, Indra, Agni, Moon, Sun, Death, and all the other deities are able to do their karmas only when they are united with their respective Shaktis. This earth, when united with Shakti, remains fixed and becomes capable to hold all beings inhabiting it. If it be devoid of this power, it cannot support even an atom."
Devi Bhagavata Purana: 3.6