I find theology and alchemy very similar. Both go to great lengths to prove something that is highly desirable for a human (afterlife and cheap gold) but very unlikely if judged with a clear mind.
That's just like if the NAME "alchemy" had been kept and continued to be used for what we now call "chemistry". Changing the name helped the bullshit die away. If it were all "alchemy" we'd have some advanced chemists but also some people continuing the bullshit and asserting that alchemy is legitimate. It's quite unfortunate to keep the name "theology" for the practice of the anthropology of religion or the history of religion.
Alchemy was not about "cheap gold". It was the study of natural elements and transformation and purification of materials. It was a proto-science which later turned into mineralogy, chemistry and medicine. It was part science, part philosophy and part occultism.