There was in a past era of the history a wise man,he had a lot of good ethics,he was honest and always helping people and feel sympathy towards weak,he never tell lie,he never steal,he never drink,he never harlot,he never hurt others,he never oppress another person..generally he was a good man who reaches the level of idealism.
This man always ordered his sons to follow him,and to be good ethiced like him,many of his sons followed him.
Years passed and the man died and the descendants still ordering their sons to follow the great grandfather teachings,many descendants followed the right teachings of their grandfather,but some of them were thinking that they were following his teachings,but they were so far away from them,they were telling lie,hurting others,stealing money of others,and oppressing others,...
People from other families saw those bad descendants,and thought that those are representing teachings of this grandfather,and that also this grandfather is bad.
They hurried without thinking,and made a wrong judgement,and judged teachings of this man through bad deeds of his sons,however if they get back to documents of this grandfather they will find that he is a good man and have great teachings.
This story is the same with Islam;
The man is Prophet Mohammad,his descendants are Muslims and people from other families are Non-Muslims.
Prophet Mohammad came with the message of Islam which is inviting to peace,love,cooperation,kindness among all people,his message was ordering not to hurt others,not to steal,drink,harlot,oppress,and this message is organizing all aspects of life from the private life of a Muslim,passing by his relations with others whether Muslims or Non-Muslim which is built on justice and kindness,and also is organizing the worship way,and many other aspects,and finally is organizing the Islamic state economically,politically,socially..etc.
And it was and still the best protocol of life for a neutral person,but in recent ages some persons or groups committed under name of Islam some deeds like bombing themselves killing innocents and some things like that which are very far from Islamic teachings and its origin.
Non-Muslim in non-Islamic countries saw those people who are killing innocents under name of Islam and hurried and made a judgement on whole Islamic religion and said that it's a religion of terrorism.They didn't give themselves the opportunity to read teachings of Islam,and read Qur'an,and teachings of prophet Mohammad(PBUH).
As for some others who read some verses Qur'an and some teachings of Prophet Mohammad they also hurried,they truly read them,but they didn't give themselves the opportunity to understand what they are reading,and why this verse or this teaching has been mentioned,and its intended meaning,they didn't read when Muslims perform the order in it and when they don't perform it,and how it's performed,and also they didn't read about sayings of Foqaha'(Muslim scholars)about these verses not justifying it but explaining them.
So a last word; Judging a religion,philosophy or thinking isn't an easy thing,but to judge a thing you must and have to be very neutral , you must judge it through its teachings not through acts of its followers because you're then judging acts of its followers not it.
And I insist in this point;you must look at what you're judging, if you're judging Islam so look at its teachings taken from Qur'an and Sunnah, but if you're going to judge deeds of Muslims so look at deeds of good Muslims same like you look at deeds of bad Muslims.