It is possible, but it is not easy. A magical spell can easily form in the astral, but then it takes quite an effort to manifest that spell onto the physical plane. Magicians typically manifest that spell using anchors such as rituals and ceremonies, or consort with spirits who have greater ability to manifest and alter reality. However, the intensity of those manifestations differs. It is possible to experience miraculous manifestations you might be thinking about. However, this requires considerable effort. For example, years of repeated rituals would help you increase the strength of your own magical power (can also be read as black flame or light of creation) to transgress the laws of reality. Obtaining divine authorities, having close relationships with spirits etc. can wield such capabilities. But they take years of effort. For beginners, it is easier to influence intangible aspects of reality, such as emotions, luck etc.