Non believer (Kafirs) need to know some simple facts about Islam people assume Islam is just another religion like their own and this is a mistake take these 3 simple facts about Islam to show my point
1. Islam has not been hijacked. That Islam has been hijacked is what non-Muslims naturally assume because they assume all religions are the same. So they further assume that some crazies must have hijacked the religion because surely no religion would actually encourage the killing of innocents. We want to believe the religion has been hijacked. Once people realize it isn't true, we can start talking about real solutions.
2. Muslims are allowed to deceive non-Muslims if it helps Islam. The principle of taqiyya is surprising to non-Muslims. Knowing about the principle helps immunize non-Muslims from the deception. They can at least not take everything a Muslim leader says at face value. You can see (and share) some excellent examples of taqiyya in the movie, Obsession.
3. Striving to institute worldwide Shari'a law is a religious duty. Many people don't realize how politically-oriented Islam is at its core. Shari'a is the law of Allah. Any other form of government is a sin. It is their duty as a Muslim to keep striving until all governments have been converted to Shari'a law. I think when kafirs understand this, they will immediately grasp the basic principle that all governments must immediately stop all concessions to Islam