From the very beginning of Christianity, the subject of icons has been a fundamental component of theology, and most especially Christology. From the 8th and 9th centuries, icons has been central to the life of Christians and reached their peak in the thought and work of theologians such as John of Damascus and Theodore the Studite, who made them the cornerstone of their theological treatises.
Byzantine theologians stressed that the imageis distinct from its subject and cannot be confused with it, and on the other hand, the icon does not share the essence of the person portrayed.