Light is one of those things we experience more than see or touch. We experience the effect of light all around when objects are illuminated or temperatures are influenced. Metaphysically, spiritual substance is the effect or reflection of divine Light, God. It is manifest in all that is good and permanent, but is never limited in matter.
In the Bible, Paul links hope with substance when he speaks of faith. He said, "Faith is the substance of things hoped for, the evidence of things not seen." (Hebrews 11:1) Paul enlarges the sense of substance from something material to an understanding and expectation of something better, something unlimited and sourced in Spirit, God. To Paul, faith, hope and substance are tangible and spiritual. They manifest the Christ, the God-power and God-presence flowing from spiritual understanding. Substance, like faith and hope, is revealed by Christ through a spiritual sense that recognizes spiritual good.