Islam can never be understood and properly dealt with outside the Bible. Here is an example: Colossians 2 from NIV version:
20 Since you died with Christ (My insertion: the Anointed One) to the basic principles of this world, why, as though you still belonged to it, do you submit to its rules: (Islam begins with the denial of the Anointed One, where the "Praised One", the muhammad was once a title for Jesus, is replaced with the "an evil one", the man named Muhammad)
21 "Do not handle! Do not taste! Do not touch!"? (My comment: Doesn't this describe much of what Islam is all about? The rules, what is haram, what is halal. These verses were written many years before the founding of Islam but when the seeds of Islam's beginning were present)
22 These are all destined to perish with use, because they are based on human commands and teachings. (Muslims incorrectly teach over and over that the Koran is from the god Allah, indirectly from him anyway through a spirit, into Muhammad's mind and then eventually written down)
23 Such regulations indeed have an appearance of wisdom, with their self-imposed worship, their false humility and their harsh treatment of the body, but they lack any value in restraining sensual indulgence.
(Islam, with all its imposed rules of worship, its rituals, washings, regimented prayers, false piety from self-righteousness and from denying their evil nature, dimpled foreheads from prayer position, required and regulated fasting, traditional female genital mutilations, all worthless in pleasing God and in forming a good soul. So the women in this Islam must be covered up to hide the Muslim male's sensual desires!)
The teachings of the Anointed One, the true praised one, convict Muslims of sin, Islam cannot tolerate this, so Islam developed to where Christians must be subdued, converted or destroyed but these vengeful actions by Muslims will never stop the truth or extinguish the light.