A highly important aspect of Christian Science is its proposition that true existence is totally spiritual. The basis of this teaching is biblical. We can learn from the Bible that there's just one infinite God, the sole creator of man and the universe, and that God is Spirit. It follows, then, that His creation is spiritual, not physical.
Perhaps we agree with the logic of this proposition but have trouble feeling the substantiality of Spirit. Or maybe from our current perspective we have difficulty realizing the practicality of this revelation. The good news is that we can begin to feel, to discern, Spirit's allness, and to enjoy the benefits of doing so. The limited view of life confined in matter doesn't change the truth, and ultimately it can't help giving way to the truth.
Nothing is more freeing, more vital, more substantial, more in touch with reality, than the perception that life—and specifically our own being—isn't really the product of genes and chromosomes and isn't imprisoned in a physical frame, but is nonmaterial, indestructible. This is essential to the metaphysical healing of illnesses, all of which stem from some facet of the conviction that life is synonymous with matter.