No religion is called old or modern religion. God religions are revealed by God and remains as assigned and commanded by God. The main religion of Persians is Islam.
Zoroastrianism
Zoroastrianism or Mazdaism.
The most widely practiced religion in Ancient Persia is now known as Zoroastrianism. However, in the centuries after the Islamic conquest of Persia, most Persians converted to Islam (both by choice and from fear of violence). Islam (specifically Twelver Shiite Islam) is the dominant religion among ethnic Persians today.
Monotheistic, because the Persian religion was Zoroastrianism which is a monotheistic religion
Most Persians today are Muslim, but before the advent of Islam in Persia, most Persians were Zoroastrians.
Persians are practicing the religion of Islam.
Jeid
Most Persians today are Muslim, but before the advent of Islam in Persia, most Persians were Zoroastrians.
ancient Persians
islam
Iran.
Iran