To the doctrine of the resurrection, in which ethical and speculative elements are thus happily blended by Paul, the new religion doubtless owed in great part its rapid success. Into an account of the causes which favoured the spreading of Christianity, it is not our purpose to enter at present. But we may note that the local religions of the ancient pagan world had partly destroyed each other by mutual intermingling, and had lost their hold upon people from the circumstance that their ethical teaching no longer corresponded to the advanced ethical feeling of the age. Polytheism, in short, was outgrown. It was outgrown both intellectually and morally. People were ceasing to believe in its doctrines, and were ceasing to respect its precepts. The learned were taking refuge in philosophy, the ignorant in mystical superstitions imported from Asia. The commanding ethical motive of ancient republican times had been patriotism,--devotion to the interests of the community. But Roman dominion had destroyed patriotism as a guiding principle of life, and thus in every way the minds of men were left in a sceptical, unsatisfied state,--craving after a new theory of life, and craving after a new stimulus to right action. Obviously the only theology which could now be satisfactory to philosophy or to common-sense was some form of monotheism;--some system of doctrines which should represent all men as spiritually subjected to the will of a single God, just as they were subjected to the temporal authority of the Emperor. And similarly the only system of ethics which could have a chance of prevailing must be some system which should clearly prescribe the mutual duties of all men without distinction of race or locality. Thus the spiritual morality of Jesus, and his conception of God as a father and of all men as brothers, appeared at once to meet the ethical and speculative demands of the time.