The causes for this marvellous growth[55:2] are found in: (a) the revolutionary teachings of Jesus, particularly the idea of immortality, which was very vague in heathen minds, and the law of love and self-sacrifice; (b) the miraculous powers attributed to the first Christians; (c) the purer and austerer morality of the early Christians; (d) the unity and discipline of the Church, making it a powerful organisation within the Empire; (e) the preparation and ripeness of the Empire for Christianity, and (f) the subjective vividness of the constant presence of Jesus with the early Christians, as explained by Paul, and their zealous propagandism. The results of this new life, brought into the world so dramatically, must be measured in terms of all subsequent history.[55:3] Every institution in the Empire was modified by this new spiritual force[55:4] so that as old pagan imperial Rome gradually fell, new Christian Rome took its place to rule all western Europe for more than a thousand years in every sphere of human activity and endeavour. The exact form of the organisation of the early Christian Church is extremely difficult to determine, because of the lack of sufficient positive authority in the New Testament and in patristic literature. The Acts of the Apostles and the letters of Paul and others to the first Christian communities tell nearly all any one can know about the origin and organisation of the Apostolic Church. From these sources it is clear that Jesus left certain great teachings, and many devoted believers in those truths. After His departure, the Apostles, not limited to twelve,[56:1] receiving authority directly from the Master,[56:2] like the prophets of old, spread the new pregnant faith over the world, organised their converts according to individual ideas and local needs,[56:3] and practically monopolised all direction of the Church.[56:4] With the increase of these Christian societies in size and numbers, came the necessity of appointing local officers, or of having them elected by the "brethren." In this way, at an early date, began the outward organisation of the Church. The development of the Jewish Kingdom of God into the Ecclesia of the Christians was a comparatively easy transition, especially for the Jewish converts. Next to the Apostles in point of time, but not authority, in the Biblical account, came the deacons. At Jerusalem the Apostles had the "brethren" select "seven men of honest report" to minister to the poor and unfortunate, and to wait on the table in the daily love-feasts.[56:5] They were installed by "laying on of hands." This democratic example apparently was followed elsewhere.[56:6] Both sexes were eligible.[56:7] The high qualifications for the office suggest its importance.[56:8]