Witch Watch: Are healers in fiction just unidentified witches?

Redford Observer, October 26, 1978

Were Mary Poppins and Rebecca, the Jewish healer in Ivanhoe really witches? Maybe, says Gundella, but one need not be a witch to practice magic. Though to be a witch one must practice the Old Religion and believe in three things: 1) a higher power or God (not necessarily The God but A God) 2) reincarnation 3) the ability to call upon that higher power to perform magic.

Obviously, there is way more involved than just believing in those three tenets though I'm not certain that there is a set amount of time whereby somebody becomes a witch. I suppose that it involves which coven the witch belongs to, who their teachers are and the individual's aptitude and desire to learn the religion.