User blog comment:McGillicuddy/Source of magic...?/@comment-27508115-20160414230225

1st theory: As said by a Wikia Contribuator, when God came to life he became at the same time the first living being (as Amara is amortal) and one of the most powerful being in the entire Universe. When he was born it has most probably unleashed an uncredible amount of energy, and it's possible that some of it energy (as the energy of Amara, as she exist since ever) persist in the actual Universe and that the formula and rituals of witches can allow them to acces Amara's residual energy(black magic) and allow psychics to access God's residual energy(white magic).

2nd theory: Magic, as the Zannas could come from the fairy realm of Avalon. It's possible that Oberon the king of fairies and creator of Avalon let the door of his world "open" and as Magic come from there it allow people sensitive to magic to draw their powers from this world and that some draw black energy which will be drift from bad fairies like the Wicked Witch of the West (these peoples will became the witches) and other good energy (these one will be the good psychics). It will be also not exclude that psychics could be the result of the babies kidnapped by Oberon's servant and that the latter had perfome experiences that gave them a sensibility to magic and to the other realms.