The differences between speech and violence are not the differences between words and acts, or between good and evil.
Some speech promotes violence, like teaching xenophobia or religious intolerance. Some violence protects speech, like the lawful actions of the police in a free society. The line between speech and violence is too blurry, they overlap too much on each other. Why can't someone publicly deny historical or scientific facts? Why can't religious people verbally express their emotions against heresy? This is not about spreading false personal accusations (like defamation) or taking advantage of someone's name or work (like plagiarism or fraud). The argument is symmetric: there should be nothing wrong about denying or showing disrespect about beliefs or to argue how unfounded are certain system of ideas. For example, it is wrong for a society to apply violence or censorship to the ones exposing Homeopathy for what it is (a placebo) and it is also wrong for the same society to prohibit the expression of homeopathic ideas (which is not the same as allowing people to sell homeopathic products branded as medicine, which they are not, but that is a matter of fraud, not a matter of free-speech).
One role of the state is to protect its citizens. The state will always classify and restrict variants of violence and speech. In the category of 'violent speech' it is common to find notions like libel, slander, obscenity, hate speech, blasphemy, incitement. Each society adapts the broadness of this category, but we will not find a society that dismiss the idea entirely. And this is because speech can be violent and every feasible society always restricts violence one way or the other.
The focus should be in the discourse's subject. Is it about people, communities, specific individuals, or is it about ideas, opinions, beliefs? People have rights, ideas do not. No one owns an idea, no person 'is' one. Every criticism over an idea should never be interpreted as violence against its believers, even if they see it that way. There’s no right to not be offended. On the other hand, a verbal and personal attack can be interpreted as a violent act, just like a punch. Only the latter, not the former, should concern the judicial system. This is the difference between blasphemy and hate speech, between mocking ideas and defaming communities. Religions are systems of ideas and rituals. A religion has followers but it is not them. The same goes with Ideologies or Corporations. All systems of belief should and must be open to criticism. Every free society that gives them protective status walks a messy and dangerous path. People are, by definition, worthy of respect. Beliefs must strive to be.