The many Gods/Goddesses in different beliefs are simply forms of worship, chosen ideals of the One, we say. We call them deities, they are aspects of The Mother. Such Divine beings are called devis or devas, super human personalities.
Through one chosen form of worship, the worshiper petitions through prayer or mantra the energies of The Goddess revealed in that particular deity. It is the essence of the deity that is revealed, and this one calls upon in order to transcend the physical existence. In yoga we call this, yoking to the one reality beyond space and time. As human beings we need a form with qualities to attach our mind to until we are able to merge into the Transcendental Self, it is not unlike other religions. The Christian religion focusing itself on the many saints, the cross. The Absolute without qualities is the Transcendental Self.
We are immersed in our beliefs of duality, and until we attain true knowledge we must continuously merge with the qualities of The Mother that best suits our nature. We then lose the sense of separateness, and are able to see The Mother in all of life, and all of life as The Great Mother.