I was talking to an Muslim soldier one time and I was asking him to tell me about his faith and some stupid dude came over and started spewing crap about Islam and the soldier was like, "See, this is why I don't discuss my religion with others and why I am not interested in converting to theirs." That made me very sad.
I am very well-versed in Islam and I think learning to understand where people are coming from, why they believe what they believe is very important for conversion. A lot of people approach people of other faiths (or even Christian denominations) in a very patronizing, disrespectful and belittling manner. Yes, there are people who chose their faith because that's how they were raised. There are those whose religion is nothing more than cultural to them, those whose religion is all about appearance but not substance. However, there are very many people who logically, emotionally and spiritually connect with whatever it is they believe or do not believe. If you go ahead and start by insulting, pontificating your faith and belief there is no way to reach them.
If one's faith is so important and so real to him, you making the person feel stupid, pagan damned or insincere is just a nail on the coffin. It is so much better to be nuanced in your approach, get people witnessing you, reflecting on their own faith, asking those difficult questions of how and why they believe. Looking for what's missing in their lives, looking for comfort, looking for support...IMO, then is when you really reach out and touch someone.
This happens to Christians quite often.
Right here, there are literally thousands of threads/posts (combined) in the OT Forum, ET, which mock, malign, bash, disrespect Christians. Many faiths have this affront upon them. And yes, when it occurs to anyone of any faith, it is very sad.
While I am not 'versed' in the Muslim faith, I can say that I am well accepted by my Muslim friends with open arms and they are likewise accepted by me. At the beginning, the end and throughout the day, we are still human beings, the one thing that we will always have in common with one another. We may not share the same faith, but our hearts do share love for one another.