Actually, as with many bits of "Wiccan lore" about "The Burning Times", this is semi-false. The real rite begins "Ring the bell. Open the book. Light the candle." That the witch would be considered an apostate is correct in that a witch or a warlock is defined as someone who has reneged on Baptism: that is, no Baptism, no witch. Actually, the Bible is used in historic witchcraft rather frequently, in that European historic witchcraft is a synecretic faith, that uses elements of Christian symbolism along with pagan survivals, bits and pieces of Kaballah, and, sometimes, simple invention. What made the opposite belief an urban legend was, of course, the popular film, which drawing from the "Discovery of Witches", also held that witches couldn't fall in love, cry or blush, and would inevitably float in water, as well as giving the name "Pyewackett" to a familiar (Siamese) cat, as opposed to an imp (form not described).
In short, this is on par with the complex exegeses written by people who, having been introduced to formal Astrology by listening to "Hair", try to square the Moon being in the Seventh House (thus indicating an unstable partnership) and Jupiter (the Father God) being aligned with Mars (the War God, and therefore in context shorthand for the Military-Industrial Complex) with Peace, Love, Recycling and Instant Nookie.
That said, I really enjoy the film, if only as a snapshot of the post-War Manhattan delineated in Grove Press's wicked little book, New York Unexpurgated. Back in the days before Stonewall and our present era of acceptance, the whole island was rife with weird little subcultures: walk down the right street, step into a bar or a gift shop, and you'd suddenly go down the rabbit hole. What you'd find there might be anything from a small ethnic minority's cultural center to a whole other world (Warlock Shoppe, anyone?), centered on sex, religion, drugs, music, food, or all of these, combined in any one of myriad ways. "Why yes, this is a Kurdish carpet, woven by Yazidi Satan-worshippers in Nineveh. Care for a glass of tea?" In the world of the film, witches sound rather like old time gay men, in that they can fool around, have friendships and blow off...steam, together, but can't really have long-term relationships or openly marry. Of course, it's better nowadays, but I can't help but think there's something lost...
I kind of wish the film would have ended with Ernie Kovacks, playing a William Seabrook surrogate, finding the company amenable, becoming a witch.
Someone leaves town, someone comes to town...