We here pretty much believe in the general correctness of our world view. We believe that we have facts and logic on our side. We are willing to explain the situation to anybody. All of these are fine things to have; but a key that often is required would be a teachable moment.
As people journey through life, they are trying some of this, and a bit of that, often driven by their world view. Or perhaps by what their family, friends, or the media tell them that they should be doing. And sometimes they realize that the results are not what they would like them to be. Often, these results are all too easily blamed on others; but sometimes a moment of introspection arrives when they doubt their approach, their behavior, and their world view.
These moments are key. These are times that they might be approached effectively. This is when the red pill might be fruitfully dispensed. But to be effective in dispensing it, one typically must be careful not to deliver it all at once. Gradually explaining the situation, letting the other person respond with at last partial acknowledgement before moving on is key. And an acknowledgement of understanding can be effective, for the red pill is a bitter pill to swallow.
And like with many medicines, regular usage over a period of time is often required for the patient to improve. So, be willing, be able, and be there.
Commenter ideas will be appreciated.