In its origin, the primary aim of the icon was to be a Holy Scripture to the illiterate. Christ came into this world both as the Word and as the Image. Essentially, this mission is common even today. Our children learn from pictures. When they are older, they can read. The icon precedes this and opens more essential theological and symbolic meanings which are hidden in the layers of paint. Icons are an attempt to represent the invisible in a way that reminds us of the supernatural and concentrates our attention on prayer and contemplation. Likewise, God very often speaks to our hearts through our eyes because the sense of sight is the most powerful of the human senses. This truth was recognized very early in the history of Christianity and was used as a means to make the Gospel better known, this being done long before the advent of the printing press.
The importance of graphic representation is evident in mural paintings, sculpture and stained glass from the medieval period. It is also evident in early iconography where the didactic purpose of some icons is obvious. However, the didactic purpose, where it appears, is always accompanied by the devotional aspect, which is the true end.