Why is Irans language Persian not Iranian

This was taken from a resolved answer in yahoo answers: (the person who answered it is named dirkaboy)

we call ourselves persian becuase our parents emmigrated from Iran before the revolution or quickly afterwards, and they raised us to call ourselves persian as when our parents arrived in America, there was a massive anti-iranian sentiment going around in the US public. Thus, calling ourselves persian would allow us to avoid confrontation and racism. Persia, however, technically refers to the southern part of Iran, which is the Pars region, with persian referring the the ethnic peoples living in that region. I, as well as many others, believe that Iran and Iranian are better names for the country and its inhabitants because Iran is a melting pot composed of mongolian-ancestry, russian-ancestry, arabs, indians, armenians, as well as the majority persians. Thus, Iran would represent all of Iran and the people that live there.

Arabs are people from arab countries such as Iraq, saudi Arabia, kuwait, yemen, oman, UAE, parts of Lebanon, syria, bahrain, and some north african countries. The reason Iranians are adamant in saying they are Iranian/persian and not Arab is becuase of the long lasting feud between Iranians and Arabs, hostorically. Also, they speack a totally different language, with Iranians speaking Farsi, and Arabs speaking Arabic. Another difference between Iranians and Arabs, which is also a main reason for the dislike of eachother is that most Iranians are Shiite Muslims, while most Arabs are Sunni Muslims.

The main language of Iran is farsi, and there are many variants of it, such as a Mazanderani form used in the north, a form used in the eastern part of Iran, and other various forms used in other ethnic regions of Iran. In general though, It is the same language.

God willing is a term that is widely used when One talks of something and wishes and hopes that it occurs, such as "God willing there will be a good harvest this year"

In farsi, it is said as "be omid-e khoda" "khoda bezare" etc.