Other Christian religions (e.g. Lutheran, Catholic, Baptist, et al.) leave access to the altar open for their congregations. Is there a special theological reason the the different approach by the Greek Orthodox churches? Or is it a cultural tradition to separate it from the Western church religions?
What is the rationale for Greek Orthodox's erection of a wall between the congregates and the altar?
2 Answers
What is the rationale for Greek Orthodox's erection of a wall between the congregates and the altar?
The altar area is and has always been considered the most sacred physical portion of a church, whether in a Catholic or Orthodox church.
Thus, just as the Temple in Jerusalem had the Holy of Holies, the Orthodox separated the sacred sanctuary of their churches from the rest of their churches with an iconostasis.
The iconostasis (icon wall or icon stand) is the wall before the altar. It represents a threshold into the most holy space; and so on it we see icons depicting the most holy figures. First and foremost is, Jesus Christ. On either side of him are the figures most significant to him in his earth life: the Virgin Mary and St. John the Baptist. The icon beside the Virgin Mary’s is the icon of the saint or life event of the Church (ours is the Dormition Tis Theotokou). Above the doorway to the altar is an icon depicting the last supper, and around it are icons of the holy apostles. - The Greek Orthodox Church
This is the traditional set up of Orthodox Churches.
This is not the same thing of the chancel found in larger Roman Catholic Churches and cathedrals. The Chanel was originally to separate choirs in larger churches, cathedrals and basilicas from the rest of the congregation. The average Roman Catholic parish church never had a Chanel erected within their church constructions, because smaller parishes never had large choirs. By contrary, all Orthodox Churches has maintained the usage of the iconostasis in their churches.
The chancel was also originally screened off in Roman Catholic churches, but under Protestant influences the barriers were eventually done away there also.
In the ancient Church the altar was understood to have taken the place of the Holy of Holies. Screening the altar follows from Jewish tradition, where the Holy of Holies was covered by a veil (Exodus 27) and could be accessed only by the priests (Hebrews 9:7). See On the Divine Liturgy by written by Germanus, Patriarch of Constantinople in the 8th century.