I agree with what has already been said, especially by Gabriel. Indeed, we as Orthodox Christians must try to be truthful in everything. The truth about Islam is, first and foremost, that it is not a homogenous teaching by any stretch. From the very beginning, Islam had, and still has, very loose structure, if at all we can talk about any "structure" while researching Islam. There is no theology as such in Islam; a Muslim is defined as someone who confesses that "there is no God but Allah, and Mohammad is the Prophet of Allah," prays in a certain way (facing Mecca, making prostrations, baring the feet, etc.); reads the Koran and considers this book holy; gives alms; fasts during the holy month of Ramadan; and, if possible, makes a "hajj" to Mecca. The "theology," however, is, essentially, what a local learned man in the mosque (the "imam") teaches, and this can be pretty much anything, from syncretism (like in many Sufi mosques) to extreme "Puritanism" (like in Wahhabi mosques).
There was a big article in "National Geographic" about Pakistan a while ago, and it said that there is a very serious revival of Sufism there; it's a very interesting "mystical" sort of Islam, very peaceful, absolutely non-violent and striving to reach unity between different peoples and cultures. The Sufi imams in Pakistan preach peace with Hindus, and really try to find some "common denominator" for the monotheist Islamic culture and the polytheist Hindu culture.