The phrase spiritual metaphysics can be a reference to the use of spiritual or mental efforts in order to achieve physical results or to the supposed gray area between the physical and the spiritual. Spiritual metaphysics is often associated with New Age beliefs, and there is no clear, widely accepted definition of the term. There are no explicit religious perspectives to which spiritual metaphysics is attached, though most contexts involving spiritual metaphysics suggest a pantheistic worldview.
The term metaphysics itself refers to philosophical views of ultimate reality: what exists and what that existence is like, in its most fundamental sense. Of course, the term spiritual is generally used to refer to those aspects of human experience that are non-physical. Spiritual metaphysics, then, becomes a term suggesting an ultimate view of reality that is, at its core, spiritual and not physical. This view generally leads to the claim that the ultimate reality is uniform, and all we experience is really part of the same ultimate truth. This is compatible with New Age and other pantheistic worldviews, which believe that “all is one.”
In actual practice, the phrase spiritual metaphysics is found almost exclusively in amateur attempts in spiritual discussion. Theology and philosophy can both be tangled up in strange terms such as logical positivism or metaphysical realism, but these terms have defined meanings and objective boundaries. Spiritual metaphysics is neither well-defined nor objective, and it effectively describes nothing. Not all attempts at spiritual thinking are reasonable, and not all lead to meaningful knowledge (see Romans 1:21). To some extent, the phrase spiritual metaphysics is just pop culture mumbo jumbo, having no particular meaning beyond what the person using it injects at that particular moment.