Yelling and showing base emotions to convince others to follow your point of view, seldom changes minds. A person needs time to absorb new ideas, analyze them, and then transform their thinking. All of this requires calmness.
Once emotions are too powerful, the person hearing the others’ point of view, is only defensive and is unable to process new ideas.
This is especially true when discussing spiritual manners. Most have their own set of ingrained beliefs. Hence, as an example, when I talk about Spiritism, I relate my experiences and what led me to discover the true magnitude of the spirit realm. If I see them growing bored with my history, I cut it short and mentally say to myself I will try another day. But, if they seem engaged, I then wait to see their reaction. Many times, they will tell me about unexplainable spiritual occurrences. Then I relate to them how everything is knowable once you understand Spiritism.