Marxism saw history as a series of class struggles.
Difference of government philosophy and differing sects of Islam.
For the Iranian Revolution, the question of a secular versus religious government was of concern. The government being overthrown was more secular and Western influence was there. The revolutionaries were fundamentalists who wanted religion to return to the government.
In the Iraq-Iran War, it was a difference of religious sides within Islam. Iraq is more Sunni and Iran is more Shi'a. These sects have a long history of conflict and the difference in religion and politics influenced the war. Also the question of western influence in the area was of concern.
They all believe in one God, their holy book derives from the Torah somewhat, they generally have the same ethics (don’t kill, don’t steal etc.)
However, Jews are still waiting for a messiah, Christians are waiting for the Messiah Jesus to come again, and Muslims are a bit of a mix, Messianism is alien to Sunni Islam but it is a central belief in Shia Islam.
