A Parable on Religion

A Persian, a Turk, an Arab, and a Greek were traveling to a distant land when they began arguing over how to spend the single coin they possessed among themselves. All four craved food, but the Persian wanted to spend the coin on angur; the Turk, on uzum; the Arab, on inab; and the Greek, on stafil. The argument became heated as each man insisted on having what he desired.
A linguist passing by overheard their quarrel. "Give the coin to me," he said. "I undertake to satisfy the desires of all of you."
Taking the coin, the linguist went to a nearby shop and bought four small bunches of grapes. He then returned to the men and gave them each a bunch.
"This is my angur!" cried the Persian.
"But this is what I call uzum," replied the Turk.
"You have brought me my inab," the Arab said.
"No! This in my language is stafil."
All of a sudden, the men realized that what each of them had desired was in fact the same thing, only they did not know how to express themselves to each other.
The four travelers represent humanity in its search for an inner spiritual need it cannot define and which it expresses in different ways. The linguist is the Sufi [scholar], who enlightens humanity to the fact that what it seeks (its religions), though called by different names, are in reality one identical thing. However - and this is the most important aspect of the parable - the linguist can offer the travelers only the grapes and nothing more. He cannot offer them wine, which is "the essence of the fruit." In other words, human beings cannot be given the secret of ultimate reality, for such knowledge cannot be shared, but must be experienced through an arduous inner journey toward self-annihilation.

-Reza Aslan; No god but God (p. 203)