When you are arguing with someone, you are really trying to convince yourself that you’re right.
Why is that? Because you’re not certain. How can you become certain? Prove it. Show it.
That is a much better, more constructive form of argument.
Loved ones still might not listen, but they are in the right not too. Their situation is different.
What you can do is to set up their underpinnings, so that they come to the realization themselves.