You won’t be invited to stand on a stage (literally or figuratively) and address a group unless you’ve earned the right to be there.

And this should be all the more reason to develop your delivery skills. You can know everything there is to know about your topic and feel passionate about it, but if you don’t have the skills to deliver that message in a way that’s engaging and pleasurable for your audience, you won’t be invited back.

A good speaker knows what to say. A great speaker knows what to say and how to get the audience to act on it.