In Islam you have orders to preach to every one your own family as well as others. And failure to preach and stop evil ALLAH and his RASOOL SAW have promised wrath of ALLAH.
There is a tariqah to how you preach as well. The first and foremost dawah that any Muslim can do is through his or her own example.
Secondly you must ensure that through your attempts for dawah, you do not push people away from the deen. Those tableeghi boys who knock on your day asking you to come to their masjid, more often than not only result in people being annoyed at having to answer the door to find those people there!
Thirdly you should take into account social norms in a society when you do dawah/tableegh. If you behave in an alien way you are more likely to have people avoid you. Your apperance/approach should not be the reason for people moving away from the deen.
My sheikh told me a great example of this. He says he's seen many brothers wandering down the street in the UK using the miswak. He said he dispairs every time he sees this. The reason is because in the UK it is not normal to brush your teeth in public. Also secondly once you are brushing your teeth, it triggers saliva in your mouth, or maybe blood if you hit a gum awkwardly. What will you do in that sitation? Spit - like a digusting camel. He said when he was in Syria the teachers would forbid anyone from using the miswak in the classroom or any public places.
When i attend my classes some people go in jubbas, salwar kameez, others go in T shirts. Some girls go in Abbayas, some wear niqab, others wear jeans. The sheikh has never once asked anyone to sit anywhere in the lecture theatre, people segregate themselves, some couples choose to sit together. If it is namaz time he asks that anyone who wishes to pray namaz should do so in the room next door, he facilitates space for ladies, but he's never asked anyone to perform namaz.
This man is not a liberal, he realises that his job is to teach the deen, not to force people away from it by forcing them to sit somewhere, or to pray or to dress in a particular manner. If he does his job correctly, his students will follow the sunnah.
Unfortunately so many of us don't have the same live and let live attitude. The post that triggered this whole conversation was based on someone jumping to conclusions and trying to fit his own ideals on someone else.
