The ideas of magic in 1100 CE was not the same as it was in 1450 CE.
Both the bible itself, and the koran and torah present the miraculous works of gods, angels and prophets, and warn against witchcraft and/or paganist ritual and recommend punishments for it. These ideas are very old indeed.
You're both right.
Influential Christian thinkers such as St Augustine and Thomas Aquinas had always considered magic to be demonic.
Many important changes took place from the High Medieval to the Early Modern periods that made the early modern witch trials possible:
- Learned magic was transmitted from the Islamic world during the High Medieval period. This made magic more intellectually respectable but also potentially more threatening in the eyes of churchmen.
- Demon summoning (known, confusingly, as necromancy) was being practised by some churchmen from the 12th century onwards.
- Satan became perceived as more powerful and dangerous.
- The idea of witchcraft as a conspiracy to destroy Christendom.
- The idea of the witch not merely as a practitioner of hostile magic but as a worshipper of Satan.
- The re-introduction of torture as part of the legal process in the 13th century.
- The early modern wars of religion.
- An increase in storms and bad harvests in the Early Modern period, which were blamed on witches.
The above is not intended as a complete list but merely to sketch out some of the many possible causes.
Michael Bailey,
Magic and Superstition in Europe (2006):
Although magic was utterly evil and demonic, Christian authorities were always necessarily confident in the superiority of divine over demonic power and the ultimate triumph of Christianity over paganism. Such attitudes are evident in Burchard's [11th century bishop of Worms] writings. Even when demonic, superstitious, and pagan magic might produce real effects and work real harm, Burchard consistently treated these practices as the foolish errors of misguided and uneducated people tricked or deluded by demons rather than as serious threats to Christian society… Despite the numerous condemnations of supposedly persistent magical and superstitious practices over the centuries, as well as some relatively severe legislation, early medieval Christian society seems to have been generally confident regarding magic.
Beginning around 1300, the level of authorities' concern over magical practices, especially harmful and supposedly demonic sorcery, seems to have risen significantly. In addition, accusations and trials for sorcery rose throughout the century.
Richard Kieckhefer,
Magic in the Middle Ages (1989):
One could summarize the history of medieval magic in capsule form by saying that at the popular level the tendency was to conceive magic as natural, while among the intellectuals there were three competing lines of thought: an assumption, developed in the early centuries of Christianity, that all magic involved at least an implicit reliance on demons; a grudging recognition, fostered especially by the influx of Arabic learning in the twelfth century, that much magic was in fact natural; and a fear, stimulated in the later Middle Ages by the very real exercise of necromancy, that magic involved an all too explicit invocation of demons even when it pretended to be innocent.
The main users of necromancy [demon summoning] were members of a clerical underworld… Their dabbling in the occult helped to heighten anxiety about magic, and at least indirectly it helped to make people nervous about witchcraft.
Catherine Rider,
Magic and Religion in Medieval Europe (2012):
The turning point came in the early fourteenth century, when Pope John XXII (1316-34) was especially instrumental in classifying some forms of magic as heresy, particularly ritual magic (since invoking demons could be seen as a kind of devil-worship) and magic which involved misusing the sacraments (because misusing the Host or other holy objects could be seen as a rejection of accepted religion). This also had important implications for the ways in which these kinds of magic could be prosecuted. By classing them as heresy, John XXII brought them under the jurisdiction of the Inquisition, which had been set up in the thirteenth century to investigate heretics.
Brian Levack,
The Witch-hunt in Early Modern Europe 3e (2006):
The great European witch-hunt could not have taken place until the members of the ruling elites of European countries, especially those men who controlled the operation of the judicial machinery, subscribed to the various beliefs regarding the diabolical activities of witches that we have briefly described above. The mere belief in the reality of the magic that witches practised was not capable of sustaining the systematic prosecution and execution of large numbers of witches. The crime of maleficium, as allegedly practised by witches in early modern Europe, while clearly felonious, was not serious enough or practised widely enough to elicit the type of judicial campaign that was in fact mustered against them. In order for the intensive hunting of witches to take place, it was necessary for the ruling elite to believe that the crime was of the greatest magnitude and that it was being practised on a large scale and in a conspiratorial manner. They had to believe not only that individual witches were harming their neighbours by magical means but that large numbers of them were completely rejecting their Christian faith and undermining Christian civilization. They had to believe that magicians belonged to an organized, conspiratorial sect of devil-worshippers.
