LDS definition: The Apostle Paul taught that "faith is the substance [assurance] of things hoped for, the evidence of things not seen" (Hebrews 11:1). Alma made a similar statement: "If ye have faith ye hope for things which are not seen, which are true" (Alma 32:21). Faith is a principle of action and power. Whenever we work toward a worthy goal, we exercise faith. We show our hope for something that we cannot yet see.