Nothing at all, as Kalthoff shows, is to be gained for the understanding of Christianity from the completely modern view that religion is an entirely personal life and experience. Religion is such personal life only in an age which is differentiated into personalities; it is such only in so far as this differentiation has been accomplished. From the very beginning religion makes its appearance as a phenomenon of social life; it is a group-religion, a folk-religion, a State religion; and this social character is naturally transferred to the free associations which are formed within the limits of tribe and the State. The talk about personality as the centre of all religious life is with regard to the origin of Christianity absurd and unhistorical, for the reason that Christianity grew up in religious associations, in communities. From this social religion our personal religion has only been developed in a history lasting centuries. Only after great struggles has personal religion been able to succeed against an essentially older form. What devout people of to-day call Christianity, a religion of the individual, a principle of personal salvation, would have been an offence and an absurdity to the whole of ancient Christendom. It would have been to it the sin against the Holy Ghost which was never to be forgiven; for the Holy Ghost was the spirit of the Church's unity, the connection of the religious community, the spirit of the subordination of the flock to the shepherd. For this reason individual religion existed in old Christendom only through the medium of the association of the community of the Church. A private setting up of one's own religion was heresy, separation from the body of Christ. [509]