The full quote from Mary Baker Eddy's book Science and Health with Key to the Scriptures is on page 99:
"The calm, strong currents of true spirituality, the manifestations of which are health, purity, and self-immolation, must deepen human experience, until the beliefs of material existence are seen to be a bald imposition, and sin, disease, and death give everlasting place to the scientific demonstration of divine Spirit and to God’s spiritual, perfect man."