Ok, so you get the self-empowerment thing, and you've proven to yourself that you've got something going on spiritually, magically or otherwise. So WHAT IS IT??!!! Some Witches believe in Goddess and God and people-entities, like Jesus and Mary. In fact, some "Catholic Witches" actually use Jesus and Mary in place of other Goddess and God names. Some use Kernnunos and Kerridwen as archetypal images in much the same way. Others will find deities they can relate to, like Kali Ma for the rape victims seeking revenge, or Brigid for the Celtic in you. Many are of the theory that the old God/desses need us to acknowledge them in order for them to exist. For (yup you guessed it) example:
The devil, as an actual entity, does not exist, however, if 5 million fundamentalists believe he does, and then 50 anti-Christians (Satanists) spend several days "conjuring him up" then, perhaps, they will see an actual devil within that smoke, talking to them like some bizarre B-movie scene and altering things in our reality. So, in such a way, thousands of people, over thousands of years, have provided food for the coagulated energy we call "Osiris" Then he does exist, and you can utilize the energy in this "psychic pool" for worship or magic.
Some of these ideas, more than others, are still playing upon the idea that deity is separate from, or even "above" ourselves. But there are other ideas, as each Witch has his/her own belief system. There is the idea that because much of nature is seen in male and female, we identify with a male and female deity. They are both one, but in order to relate to them better, we distinguish between the two. Theories from other traditions abound in books and on the internet.
My personal idea (you can view other trads here): matter is energy, light is energy, sound, everything is energy. It has no good, and no evil, it just is. Because we are intelligent enough to glimpse this energy, and because we attempt to utilize it to our wills, we hold a special responsibility. We are responsible for changes in the universal web that we have caused. Any high school science teacher will tell you that when two objects touch, each goes away with some of the other. When you wear a copper bracelet, some of the copper is deposited in your epidermis. Close inspection of the bracelet will show skin cells attached to it. When you talk to a person, ideas are exchanged in much the same way. These are all exchanges of energy; matter in the former, and thought forms in the later. In a small way, this explains how connected we all are. The universe, the earth, people, plants, etc. everything is connected. Kirlian photography shows that plants from a house whose owner has died are very different from those same plants two weeks earlier. Talking to plants is an old time technique that really works, and whether you believe that it is the increased carbon dioxide from human breath, or is the energy of love being fed to the plant, it shows that we are all interconnected. The dust in the corners of your house is a high percentage of "star dust" or fallout, as tons of debris from space enter our atmosphere every day. There is no REAL dividing line, understanding this is easy, KNOWING/FEELING this, utilizing this knowledge, and remaining sane, is "walking between the worlds" So deity to me is energy, the universal energy, even pockets of energy that we call "Pan" or "couch" or "electricity" This energy takes infinite forms and "frequencies" but I feel that generally it works in a spiraling manner. Like DNA, the Milky Way, fractals, water flowing down a drain (water flow indicates energy movement- clockwise/doesil in the northern hemisphere, counterclockwise/widdershins in the southern-hence the invocation of the circle/sphere is done accordingly) However, identifying with an archetype, whether it is Diana, or the High Priestess of the Tarot, can aid in self exploration and improvement. And, identifying with an archetype can help you to draw on a specific type of energy. This energy, to me it seems, has an ordered nature, even a consciousness.