What is the role of the Fresco in the play?

In Pentecost, various characters form different opinions about the fresco, especially about who painted it and when. It is located in a church in the (unnamed) Eastern European country where the play is set. Previous to the time when the play's action begins, the fresco had been covered up with another wall and some political propaganda.
Although the fresco depicts a national epic, its style seems that of the famous Italian painter Giotto, and if it were by him it would be considerably more valuable. The local art scholar, foreign art historians and businessmen, and priests and ministers are among those who argue about its provenance and proper disposition—should it stay, or should it be removed?
As political unrest is added to the mix, including a complex hostage situation, another voice claims it is an Arab work, not Christian at all. The value of an old art work contrasted to the lives of the people in the church is debated, leading up to a climax of violent destruction.
The importance of the work to the art history and cultural world is a constant subject of debate, placing the fresco at the center of irreconcilable political differences. In addition, since the fresco is a religious subject and painted in a church, it can stand for conflicts over religious beliefs more generally. And, since a fresco is a painting on a wall, it could mean to symbolize the Berlin Wall, which was recently demolished when the play was written.