But this imperious claim of a Kingdom upon its members is not peculiar to Christianity. It is the law in all departments of Nature that every organism must live for its Kingdom. And in defining living _for_ the higher Kingdom as the condition of living in it, Christ enunciates a principle which all Nature has prepared us to expect. Every province has its peculiar exactions, every Kingdom levies upon its subjects the tax of an exclusive obedience, and punishes disloyalty always with death. It was the neglect of this principle--that every organism must live for its Kingdom if it is to live in it--which first slowly depopulated the spiritual world. The example of its Founder ceased to find imitators, and the consecration of His early followers came to be regarded as a superfluous enthusiasm. And it is this same misconception of the fundamental principle of all Kingdoms that has deprived modern Christianity of its vitality. The failure to regard the exclusive claims of Christ as more than accidental, rhetorical, or ideal; the failure to discern the essential difference between His Kingdom and all other systems based on the lines of natural religion, and therefore merely Organic; in a word, the general neglect of the claims of Christ as the Founder of a new and higher Kingdom--these have taken the very heart from the religion of Christ and left its evangel without power to impress or bless the world. Until even religious men see the uniqueness of Christ's society, until they acknowledge to the full extent its claim to be nothing less than a new Kingdom, they will continue the hopeless attempt to live for two Kingdoms at once. And hence the value of a more explicit Classification. For probably the most of the difficulties of trying to live the Christian life arise from attempting to half-live it.