Oh, Dale! You sometimes come across as a one-drum person! If you think MacDonald meant this as a cudgel for believers to apply to others, then you mistake MacDonald’s spirit if you think to find comfort in his words.
Let me just put it this way - as particularly feisty and intelligent friend of mine once so aptly put it - something like this (and you need to imagine this being spoken by somebody with a twinkle in her eye):
If you just aren’t able to fathom that something could possibly apply to you, then just take the baby step of observing how spectacularly well it applies to everybody else!