The Let Them Theory by Mel Robbins has been praised across social media as a "life-changing" philosophy, yet one wonders if the buzz is more about clever marketing than meaningful substance. At its core, the book delivers a single, painfully obvious message: you can't control other people—only your reaction to them. This is a truism so well-worn...

“For to everyone who has, more will be given, and he will have abundance; but from the one who has not, even what he has will be taken away.” — Matthew 25:29

Though the idea of The Matthew Principle originates in the Bible, our focus here is secular. We are not discussing salvation or divine reward. We are exploring a law of reality—observable,...