Throughout the ages, Satan has been seen as God's implacable enemy, fiercely determined to keep as many human beings as he can from entering the heavenly kingdom. But according to Henry Ansgar Kelly, this understanding dates only from post-biblical times, when Satan was reconceived as Lucifer, a rebel angel, and as the serpent in the garden of Eden. In the Bible itself, beginning in the book of Job and continuing through the New Testament, Satan is...