Thank you for your responses. By belief in magic, I mean the ability of any finite agent (e.g. a human being or a spiritual being) to bring about changes by an act of will. My definition is thus very similar to that of English occultist Aleister Crowley (1875-1947), who defined magic in his book Magick (London: Routledge and Kegan Paul, 1986, p. 31) as “the Science and Art of causing change to occur in conformity with Will. ” (I quoted this definition in my OP.)
My objections to belief in magic are as follows:
(i) it would require material objects to additionally possess the spiritual property of being responsive to the wishes of the agent who is doing magic;
(ii) more precisely, it would require material bodies to possess semantic properties – for instance, that when magician X wishes that P, body B will move this way, but when magician X wishes that Q, body B will move that way;
(iii) it would destroy the metaphysical unity of a body’s properties, by adding extra ad hoc spiritual properties which are in no way related to its material properties, thereby preventing us from ever being able to grasp all of its properties by virtue of a single, unifying concept (as sodium’s properties are said to flow from its atoms’ having 11 protons in their nuclei);
(iv) it involves the absurd and childish belief that agents can bring about changes in the world simply by wishing for them - which is ridiculous, because wishing for something doesn’t make it happen.
Re the Bible: I agree that it doesn’t say that angels are thought and volition alone, but virtually every Christian theologian who has ever written about angels took this view (Origen is the sole exception that I know of), and argued that angelic appearances to human beings involved them assuming a body which was not really theirs.