Feeling worthy is an excellent tool to build a successful skillset. But, as with any tool, theory isn't enough. Practice is the only way to become competent. I found the safest, most supportive place to practice was in Toastmasters. Positive feedback smoothed the rough spots and turned me into a relaxed, confident and effective speaker and teacher. And when relaxed I can even get an audience to laugh. That's a goal as worthy as sharing knowledge and motivation.