From 337 to 527 AD there were many Germanic invasions on the western half of the Roman Empire and the Empire fell. During this time, the Cappadocian Fathers and the Monophysite controversy solidified Eastern Christian thought in the ever-changing society and one of the results was the development and elaboration of a specific Christian art.
Cyril Mango writes that in the second half of the fourth century, Christian pictorial art changed from landscape and pastoral scenes to a kind of didactic, biblical iconography because new Christian converts who could not read were instructed in religious doctrine with explicit picture-stories drawn from the Old and New Testaments. At churches where martyrdom had occurred, picture stories illustrating the feats and sufferings of the martyrs were also created. The practice of displaying portraits of popular saints, bishops and scriptural stories in homes was also slowing occurring. Mango further documents that the Eastern Church Fathers, St. John Chrysostom and St. Cyril of Alexandria, spoke with approval of this imagery and regarded it as a didactic and encouraging aid to those learning about the faith. St. Basil’s famous comment spoken in relation to imperial art and not religious art, “the honor shown to the image is conveyed to its model”, became the slogan in the eighth and ninth centuries of the Iconodule party.
The icon is more than a means of instruction though. When an icon is blessed by a priest, it becomes an existential link between the human and the divine. Standing in an Orthodox Church surrounded by icons, the believer can have the feeling of being surrounded by family and experience communion and fellowship with Christ and the saints. It is for this reason that the icon is also referred to as a window to heaven.
 Cyril Mango, The Art of the Byzantine Empire 312-1453: Sources and Documents (MART: The Medieval Academy Reprints For Teaching, No. 16) (Toronto, Buffalo, London in association with the Medieval Academy of America: University of Toronto Press, 1986), 22
 Cyril Mango, The Art of the Byzantine Empire 312-1453, 22
Cyril Mango, The Art of the Byzantine Empire 312-1453, 22
 Cyril Mango, The Art of the Byzantine Empire 312-1453, 23