The Christian narrative is of Jesus living and teaching and dying (substantial) and returning, perhaps better, remaining—as spirit (insubstantial). But how to speak of the insubstantial? In the various narratives of the early Christians, spirit is said to be like water, breath, wind, or fire. The insubstantial is spoken of in terms of the substantial. The experience of spirit is felt as water, refreshing, enlivening, sustaining; as breath, soothing, gentle and essential; as wind cleansing and disturbing; or else as fire, warming and enlightening. Insubstantial spirit takes on the character of substantial matter. But, what other language is there?
In the dominant western traditions we have most often spoken of the natural and the supernatural as separate and distinct—of creation and God, the material and nonmaterial, the spirit and the body. Often, this dualism is all but absolute. The substantial, in this way of seeing, is natural, and the insubstantial is "super-nature," something outside of, above, and distinct from mere nature. But why make such a move?
The dominant dualisms (either religious or secular) lead quickly to a way of seeing that denies one or the other: either the substantial or the insubstantial alone remains "real." Some, more so in the east than the west, would deny the reality of the material world. In the west we are more likely to adopt a materialist reduction that sees mind as merely epiphenomenal of brain, of matter—that is, the material is "more real" than the nonmaterial.
The reduction of all to insubstantial seems far-fetched and untrue to everyday experience in a substantial world. But so too, to reduce all experience to the substantial, the material, seems too limited an account of experience, and hence, unhelpful. To be told that my feelings are merely the interactions of material processes in the brain—which alone is real—does not help me with my lived experience of love, hate, fear or joy.
These days I find it more helpful to think that nature is "all that is," that substantial and insubstantial are alike natural, that the "supernatural" is entwined with, embedded in, or else an aspect of, nature.
This is easiest to see with regard to the the insubstantiality of mind. Thought and imagination are surely natural, but at the same time insubstantial. Love and hate, too, are insubstantial but also natural. It seems reasonable, then, to say that spirit, too—the divine spark in all—is insubstantial yet also natural.
In the philosophy of Laozi, the substantial is yin and the insubstantial yang. Both are aspects of all natural phenomena; neither more important than the other. At times the substantial is dominant, yet hidden within is the insubstantial, and the substantial will move inexorably toward the insubstantial, until the insubstantial becomes dominant. And the process of change continues.
The first followers of Jesus had known their mystical teacher as "substantial" in day to day interactions. After his death they continued to know Jesus, but now as "insubstantial," as spirit, present with them in ways they could only describe with joy as water, breath, wind and fire—a celebration of all that is good in the world.
+Ab. Andy