Rosemary Guiley (1950-2019) was an American author and researcher known for her extensive writings on spirituality, the occult, and the paranormal. Her prolific career spanned over four decades, resulting in more than 49 books, including numerous encyclopedic works. Guiley also engaged with the public as a radio show host and a frequent guest on paranormal-themed programs. Her contributions extended to board directorships for organizations focused on mysterious phenomena and extraterrestrial encounters. She received recognition for her work in the paranormal field, including a Lifetime Achievement Award. Guiley's research and writings were translated into multiple languages, and she appeared on various television networks discussing her areas of expertise.

Rosemary Guiley authored a substantial body of work exploring a wide range of esoteric and paranormal topics. Her books often served as comprehensive references, such as 'The Encyclopedia of Witches and Witchcraft,' 'Harper's Encyclopedia of Mystical & Paranormal Experience,' and 'The Encyclopedia of Angels.' These works delved into subjects like mythology, New Age beliefs, and spiritual phenomena, providing detailed explorations for readers interested in these fields. Guiley also documented geographical locations associated with mysteries in 'Atlas of the Mysterious in North America' and examined entities such as vampires, ghosts, and demons in her encyclopedic series. Her writings frequently aimed to demystify complex subjects and present them in an accessible format.

Beyond her prolific writing, Guiley was actively involved in disseminating information about the paranormal and supernatural through various media platforms. She hosted a radio show and was a regular guest on 'Coast to Coast AM,' a popular program known for its focus on paranormal and unexplained topics. Guiley also made television appearances on networks like A&E, The History Channel, and The Discovery Channel, further extending her reach. Her work was translated into 14 languages, indicating a global interest in her research. She participated in numerous conventions and events, including the International U.F.O Congress and Conference, engaging directly with enthusiasts and researchers in the field.

Guiley's perspectives on spirituality and the paranormal sometimes drew criticism. For instance, Christian evangelist John Ankerberg challenged her views on intuition, as expressed in 'Harper's Encyclopedia of Mystical & Paranormal Experience,' suggesting that such beliefs could lead to a disregard for rational thinking and spiritual discernment. Ankerberg also interpreted her book 'Angels of Mercy' as potentially promoting uncritical trust in spiritual entities, warning that New Age writers might be unknowingly interacting with negative forces. He specifically questioned her assertion that angels should be trusted unconditionally, arguing that such an approach is irrational and leaves individuals vulnerable to deception by demonic entities.