1910. anniversary of the death of Saint Clement of Rome, the third successor of Bishop of Rome, celebrated a few years ago († 101), became an opportunity to remind his teaching, which he left in the Epistle to the Corinthians, written by him. The content of this letter is an important witness of the emerging church organization. That, what was happening in Corinth and, without a doubt, in Rome, is one of the stages of the Church’s history of major importance. The contemporary situation related to the authority prompted the acceptance of the institutional proposal based on the Holy Scripture and the practice of the Apostles. Transferring saving mission “from hands to hands”, called apostolic succession, proved to be an extremely important achievement of the early Church to preserve its credibility in the following centuries. Saint Clement of Rome is one of the first witnesses of such message and he is also the author of this essential ecclesiological element. The letter that was sent to the inhabitants of Corinth contains the earliest foundations which, after years, become an essential criterion of Catholicism. The original foundations of theological thinking can be already seen in the teaching of Saint Clement. Many later theologians referred to this doctrine, adding further ecclesiological consequences emerging from it.