Religiosity of Iranian people is its most striking cultural feature - it pervades all aspects of Persian life. "There is only one God" it's the essence of Islam, and that it is the people's duty to believe in and serve Him in the manner that is laid out in the Quran. "Islam means submission and a Muslim is one who submits to God's will" In Arabic.  The most visible daily expressions of Iran's brand of fundamentalist Shi'ite Islam are the modest dress code and behavior at mosques. The national language of Iran is Farsi, also known as Persian, an Indo-European language. The Arabic script was adapted to Persian after the introduction of Islam, but there is no standard method of transliterating Persian into English. The other main regional languages are Azari, Arabic, Kurdish and Lori (which spoken by the Lors); and there are dozens of other tongues throughout the 26 provinces, such as Baluchi,  Gilaki and Turkmen.
In Iran, as in all other Islamic societies, art favours the non-representational, the stylized and the derivative. Many Persian art forms predate the Arab conquest, but since nearly all of them reached their peak within the Islamic era, religious influences are rarely absent. Iran's most famous cultural export are Persian carpets, dating back to the 5th century BC, and are still an integral part of religious and cultural festivals. The most appealing and melodious traditional music is found among the ethnic minorities, such as the Turkmen, Kurds,  Azaris and Lors. Persian poetry first appeared in the 9th century AD, and slowly developed into the enduring canon of epic poems and non-rhyming couplet poems which are part of its cultural treasury today. Persian painting dates back to the Seljuq period, which then faded until the 16th century when it flourished along with calligraphy, especially in Shiraz. Other perfect Persian handscrafts are glassware, metalwork and woodwork, while, more recently, Iranian films have been remarkably successful.