Judge by actions.
The Muslim Brotherhood government in Egypt has vowed to destroy the Pyramids as "pagan" symbols. Muslims in Iran have already destroyed several Buddhist relics for the same reason - their Prophet is so insecure that he cannot abide any competition.
Muslims routinely strap on explosives and kill dozens and hundreds of people, innocent Muslims and "infidels" alike, again in accordance with their holy Koran, which preaches that a Muslim who dies in the fight against the "infidel" is assured of a place in Heaven with those 72 virgins we hear so much about.
Muslims routinely force their women into concealment at best, slavery at worst, including beatings and mutilation, again all in accordance with their holy Koran. If you do a search on "Islam women's rights", however, you find dozens of articles that show Islam to advocate equality of men and women in many areas, while still requiring Muslim women to obey restrictions on their freedom for religious reasons. If only reality matched these rosy visions!
Muslims advocate canings for women who are viewed as immoral, and stoning for those accused of adultery, despite this punishment not being prescribed in the Koran.
Muslims in Africa have an unbroken record of enslaving and trading in human beings that reaches back over 1000 years.
Islamic art is limited to narrow subjects. Depicting the Prophet is forbidden, as is any music that does not meet the requirements of the current crop of mullahs. This leads to some ironies, as when the religious leaders in Iran celebrated Freddie Mercury as an Iranian hero for his music with Queen. All other music - and TV shows - are forbidden.
Islam encourages pedophilia.
Islam requires unbelievers living in Muslim areas to pay ransom regularly to be allowed to live in comparative peace.
Islamic leaders have the power to declare "fatwa" on anyone who runs afoul of their personal idea of what is allowed and required by Sharia law. The death sentence on Salman Rushdie is still in effect over 20 years later.
Now, other major religions on our planet have in the past advocated and actively pursued similar atrocities against individuals and historical artifacts. The big difference is that Judaism and Christianity and most Eastern religions have grown out of the barbaric practices of the past, and leaders of most modern religions preach peace, love, and tolerance. Islam, at present, has few leaders willing to publicly condemn the barbaric practices seen daily in our world - indeed, far too many Islamic leaders aid and abet these practices.
During the 19th century, many Islamic practices were made more in keeping with modern civilization, and Muslim people began to integrate into the modern world. In the last 50 years, however, "fundamentalists" have taken over leadership of the Islamic world.
Western civilization is at a crossroads. Either we resist Islamic barbarism and defeat those who would destroy us, or we either convert to Islam or accept the precarious status of "dhimmis" - and kiss freedom goodbye.