Some persons, for instance, never are, and possibly never under any circumstances could be, converted. Religious ideas cannot become the centre of their spiritual energy. They may be excellent persons, servants of God in practical ways, but they are not children of his kingdom. They are either incapable of imagining the invisible; or else, in the language of devotion, they are lifelong subjects of “barrenness” and “dryness.” Such inaptitude for religious faith may in some cases be intellectual in its origin. Their religious faculties may be checked in their natural tendency to expand, by beliefs about the world that are inhibitive, the pessimistic and materialistic beliefs, for example, within which so many good souls, who in former times would have freely indulged their religious propensities, find themselves nowadays, as it were, frozen; or the agnostic vetoes upon faith as something weak and shameful, under which so many of us today lie cowering, afraid to use our instincts. In many persons such inhibitions are never overcome. To the end of their days they refuse to believe, their personal energy never gets to its religious centre, and the latter remains inactive in perpetuity.
In other persons the trouble is profounder. There are men anaesthetic on the religious side, deficient in that category of sensibility. Just as a bloodless organism can never, in spite of all its goodwill, attain to the reckless “animal spirits” enjoyed by those of sanguine temperament; so the nature which is spiritually barren may admire and envy faith in others, but can never compass the enthusiasm and peace which those who are temperamentally qualified for faith enjoy. All this may, however, turn out eventually to have been a matter of temporary inhibition. Even late in life some thaw, some release may take place, some bolt be shot back in the barrenest breast, and the man’s hard heart may soften and break into religious feeling. Such cases more than any others suggest the idea that sudden conversion is by miracle. So long as they exist, we must not imagine ourselves to deal with irretrievably fixed classes.