Freedom of speech does not mean freedom to offend.

Freedom of speech and freedom to offend.  Both is totally different from one another. 

If you look at the lecture of zakir naik or any other Islamic scholar you will notice that most of the time they offend other religion. And we do as well in our dealy life.  If you tell them you don't have the right to offend other religion. They will definitely say they have the right to speak freely. 

So we can tell here freedom of speech is the freedom to offend.  

You can't encourage anyone without offend something on something.  Our human nature buildt that way .