Hello, my personal experience in trying to break controversial topics with people has been in keeping it light, and keeping the perspective that I speak from, in a place where I keep my attitude calm, and do not become offended when other people disagree with me.
Having the truth, the no doubt about it, yes indeed - THE TRUTH - should allow you to feel in comfortable in any situation UNTIL you ego feels like it's running out of rope.
Now this is where we can reflect on our self, and the other person. The chances are if they are getting upset, about something that makes sense to you but not to them. Then I suspect that they are operating in a place of thought they don't have too well figured out on their own. And the same is true if you are the one to get upset.
A lot of the time, people say they want to help you, and give you the truth but the fact of the matter is, they just want some one to believe and buy into their prescribed version of "truth".
The truth is, everything is referenced back to principals established by your SELF. The light patterns that make the structure of the letter A, have been defined to you, BY you, in your own unique way. Some one once showed you, HERE THIS IS THE LETTER A, but the shape as defined by the light arrays that meet your eye balls are free to be interpreted in your own unique way. I could give you what I believe to be the letter A and ask you to match it, but what you see is the same pattern you have defined by your own means, and thats what you show me in reflection to say that YOU have mirrored the letter I gave you. But as I take the information I reinterpret it to my own understanding every time no matter what unless I myself choose to expand upon what I once percieved to be the letter A.
That is the truth. And so, you and another person can talk about a THING and say yes you both agree. But all you are really saying is that the thought patterns as regurgitated by another person seem to match the thought patterns that you have given out. And how we judge that is by pattern recognition and how close to perfect one pattern matches another.
But this isn't in fact considered an agreement, this is just "OKAY THE WORDS WE SAY ARE THE SAME IF NOT SIMILAR" but who takes the time to make sure you value those words the same?