The All

The All is a spiritual energy which runs through everything that exists since when the world was a dark and tumultuous place.

Neither good nor evil, it's part of the Earth, the air, everything. The Nexus of The All is much more powerful than the Nexus of the Halliwell Manor. The All is the basis of all magic.

Beginning of Magic
Thousands upon thousands of years ago, a woman came across that Nexus. She alerted her mate to what she had found. At first, they were too afraid to go near it. Even at a distance, they could feel it's power. But she pushed past that fear and tapped into this power. She was infused with more of the All than any human was intended to possess. The woman shared that power with her mate and it changed them, making them immortal and invulnerable.

It bonded them forever to one another and to the All, creating a state beyond consciousness beyond the known physical universe: The Higher Realm, a place of pure and utter bliss that they shared with the All. But their presence there affected the Earth. Their magical bond contained the All in the Higher Realm. The world started to die. The only way to save it was to separate the powers. To allow the power of the All to flow freely again, the woman and man were forced to abandon the Higher Realm, never to return again.

Origins of Witchcraft
Once back on Earth, the woman gave birth to a pair of children that were conceived while she was in the Higher Realm. The first child had powers like her mother, just not as stron

The Source of all Magic is the origination of all forms of magic. It can be tapped into on All Hallow's Eve[1]. Not much is known about it, as it was only mentioned by Eva.

The Source of all Magic might be a reference to The All, which was revealed to be a spiritual energy that runs through everything in existence and the basis of all magic.

It is from her that most natural born witches descend. The second child was born with the same abilities, but he twisted the magic for darker purposes and gave rise to warlocks. The other children they had, the ones that came later, had no powers to speak of, but they and their descendants could tap into the magic as witch practitioners. In very rare cases, these non-magical descendants can give birth to a full witch.

Everytime a witch is born, he/she inherits a tiny piece of the All, not a lot, but just enough to have an active power. With every new descendant, the All began to weaken, it was spread too thin. It needed to reclaim some of the magic it had lost, it needed one of them to return, this was part of the Grand Design. The Elders were forced to make a decision. Neena's mate returned to the higher plane, but he didn't abandon her, not by choice. One day, he was just gone and the woman was alone for the first time in forever.

On All Hallow's Eve of the year 2000, the Charmed Ones were sent back in time to the 17th century by the witch Eva and her coven in order to save Charlotte Warren who was kidnapped by the evil witch Ruth Cobb in an effort to raise her daughter to be evil as she was prophesied to be a very powerful witch. As they or their powers didn't really exist in the past, the sisters had no access to their active powers so they were taught how to tap into natural magic by Eva. This was simple as the All can be easily tapped into on All Hallow's Eve, the day when magic is the strongest.