I knew full well going to Facebook to ask for advice could be dicey. My wife and I had had our fill of mechanic bills and were in the market for a new (used) vehicle. Searching online for low-mileage, well-maintained cars in our price range was proving difficult, but I thought I’d found a good lead. The car was about 15 years old but appeared to have barely been driven by its one owner. It was in great shape and seemed like a steal.

There was only one problem. It was a BMW.

Am I a BMW guy? I thought to myself. My first concern, I confess, was about what others might think. So I took to Facebook and asked, “Anyone out there think it’s problematic for someone in my position to drive a car like this?” I was worried it might appear immodest or even hypocritical for a seminary professor and preacher of the (free!) gospel to be seen driving such a car.

I made sure to mention a few exonerating details—that it wasn’t new, wasn’t expensive, and the like. Most ...