Number one: all religions are fundamentally undemocratic because at their root they place religious revelation, doctrine, and scripture above human-made laws.
But in today's world Islam is particularly undemocratic.
Perhaps in theory religions equally defer to "God's law" but not in practice. To claim equal religious fervency is to be ignorant of history. "Adherence to a faith" is a slippery concept, but since the Reformation Western societies have been deriving their laws and morals from increasingly secular sources. The same trajectory is not apparent in the Muslim world.
Combine the dominant hold that Islam has on its followers with the specific doctrines laid out in its holy books and you will begin to understand why Islam is fundamentally undemocratic. But I stress you must do your homework. Start by actually reading the Koran, and when you do understand that to Muslims this is the bedrock of their faith, a "miracle" in fact, the perfect word of Allah as delivered by His messenger, the prophet Muhammed. Next, absorb the CONTENT of Koran. You will not have to search hard for verses that promote inequality by demoting women, homosexuals, and non-Muslims among other groups. I would argue that equality of citizens is fundamental to democracy. I will concede that Western democracies only granted women the vote less than 100 years ago and homosexuality only ceased to be illegal in the last 50-60 years. But these progressive changes are further legacy to the Reformation and Enlightenment some 500 years prior, and they underline the fact that progress takes time. Muslim apologists who point out that in Muslim countries like Turkey homosexuality is not illegal shouldn’t take too much comfort in this technicality, but instead be reminded of the prevalence of so-called “honour killings” of homosexuals, and state-sanctioned bans of movies for “violating public morals”. To the extent that such bigotry remains in a “moderate” Muslim democracy like Turkey is in large part due to the position of authority Islam still enjoys there. Muslim apologists will further protest that the Bible has equally deplorable passages, and I would agree. But once again I remind them tha thanks to the legacy of the Reformation and the Enlightenment 500 years ago, Christians no longer read the Bible with the same degree of literalism that Muslims do the Koran, the "perfect" book of Allah.
The next major difference between Islam and other religions is that it imposes a codified law on its adherents. I'm not talking about something as simple as the 10 Commandments. Sharia Law is a complex system of jurisprudence administered by Muslim clerics. The average Muslim does not get to change Sharia Law when new evidence shows change is merited. Such a move would be heretical because Sharia Law is ultimately derived from the Koran, the "perfect" word of Allah. This inflexible, dogmatic mentality is fundamentally undemocratic.
I would only add that I welcome all rebuttals provided they come with a spirit of openness and respect - both fundamental qualities to democracy.
Muhammed called on all of his followers to perform jihad, that is "to struggle'. Struggle to do what? To struggle to impose the undemocratic Sharia Law upon all conquered lands until Sharia rules the world and all other systems are wiped out. Then, according to Muhammed's twisted logic, Allah will raise the dead from their graves and take them all to Paradise to join the martyrs already there. Perhaps that's where he will get the (formally dead) 72 virgins to give to each martyr?
Separation of Church and State. Equality of men and women. Religious freedom, freedom of thought and of action within the limits of secular laws. Equal treatment for all citizens regardless of gender, race, religion, sexual orientation. The Qur'an sets out all-encompassing social, religious, and economic strictures that make these basic tenets of a modern democratic society difficult to the point of impossible to achieve in countries where the dominant religion is Islam. The Holy Book as set out by Mohammed cannot be changed; there is no one "head" of Islam who can moderate and update the surahs and the ideas within them, which represented an advance in their time in 800 a.D. But now hold back entire countries from meaningful progress in all fields of endeavor. And unfortunately, the example of Mohammed, as set out in the Hadith and sunnahs of the Prophet also relate to a time long past but are emulated and used as justification today by radical Islamists for their actions, which are directly opposed to the "respect for the other" that is the basis of democracy.
Like this article says, just look at the documentary evidence- the Koran. It is a prescription for total control of the minds and actions of it's followers. It is a classic example of one man, in this case Muhammad, imposing his ideas and will on other people for the simple reason that his arrogance and ego can't handle any kind of criticism. I really feel sorry for people born in Muslim countries. They are heirs to tyranny at every level of their lives.
In Islamic societies the condition of being Muslim is inherited at birth and can't be renounced. This lack of religious freedom make Islam the only basis for laws and constitution of governments and its institutions, despite the existence of non-Muslim minorities, often living under threat or harsh conditions.
Democracy requires freedom and Islam is repressive towards religious freedom and other fundamental freedoms that support democracies.
Islam is no more incompatible with democracy than any other religion; religions believe that a higher power is ultimately in control of everything, but the degree to which followers of a religion respect God's law vs. their country's law varies widely person-to-person and population-to-population. Islam shouldn't be singled out because there have been high profile examples of extremism by Muslims.
No, Islam is not fundamentally antidemocratic. But radical Islam is. As we've seen it throughout history, whenever religion equals radicalism there is a danger. The 12th Century Roman Catholic Inquisition is an example of how radical religion can be million miles away from Democracy. And today, countries led by Sharia (Religious law of Islam) tend to be antidemocratic. However, countries such as Turkey, where Islam is the predominant religion but where Sharia is not established as the law of the country, democracy is established.