[dread78645]

Iranians were Zoroastrian for hundreds of years before the invasion of Islam from the west from Arabia.

At least. Cyrus the Great captured Susa in 538 BC, and moved the capital of his empire there. The Muslims didn't show up until 639 AD.
So Susa was under Zoroastrianism for 1176 years.

[eleni121]

628 BC Zoroaster was born. This religion has been around for well over 2000 years.

And Christianity as well for at least 2000 years.

http://www.iranchamber.com/religions/history_of_christianity_iran1.php