Oliver Prescott Hiller, God Manifest (1858)
“ The Scripture answers that question: "Wickedness burneth as a fire." [17] Spiritual fire, then, the everlasting fire into which the evil are to go,—is wickedness: and they are described as going into that fire, because that fire is already in their own hearts: for just as "the kingdom of heaven is within" us, as the Scripture declares, so the opposite kingdom of hell is properly within us: it is essentially a state of the mind, rather than a place;—though, after death, the state of mind becomes a place, or forms to itself a place. ”
