With all of the different possibilities out there, people can often get confused. There are so many viewpoints to choose between; how are they ever going to decide between them? More importantly, with all of this competition in the marketplace of ideas, how likely is it that they'll end up picking your view rather than one of the alternatives?
People don't like having difficult choices to make. For their own sake, you should simplify. In a technicolour world, what people really want is to see things in black and white. You can help.
If it looks as though someone isn't going to be persuaded by your view, then frighten them with an alternative:
"You don't want to put sun cream on? What, you'd rather have cancer?!"
"Slow down or you'll kill someone!"
Once you've narrowed the options in this way, people will see much more clearly the wisdom of your position.