"Faith is the assurance of things hoped for, the conviction of things not seen," wrote the author of the epistle to the Hebrews. Reflecting on this verse and the epistle's description of the high priestly and sacrificial ministry of Jesus Christ, Swiss Reformed theologian and exegete Heinrich Bullinger defined faith as "the most constant mental certainty, which rests on those things to which all our hope is directed, namely . . . the expectation...