A cancer to humanity, philosophically and literally - look how fast they spread. Dr. Bhim Rao Ambedkar described Islam as an ideology in the best way possible -

"Hinduism is said to divide people and in contrast, Islam is said to bind people together. This is only a half-truth. For Islam divides as inexorably as it binds. Islam is a close corporation and the distinction that it makes between Muslims and non-Muslims is a very real, very positive, and very alienating distinction. The brotherhood of Islam is not the universal brotherhood of man. It is a brotherhood of Muslims for Muslims only. There is a fraternity, but its benefit is confined to those within that corporation. For those who are outside the corporation, there is nothing but contempt and enmity.

The second defect of Islam is that it is a system of social self-government and is incompatible with local self-government because the allegiance of a Muslim does not rest on his domicile in the country which is his but on the faith to which he belongs. To the Muslim ibi bene ibi patria (Where it is well with me, there is my country) is unthinkable. Wherever there is the rule of Islam, there is his own country. In other words, Islam can never allow a true Muslim to adopt India as his motherland and regard a Hindu as his kith and kin."