A number of years back the codfish industry on the northeast coast of the US had a problem. The fresher the fish the better. So how could they keep the codfish fresh while they transported them across the country? When they froze the fish they lost too much flavour. When they transported them live in tanks filled with saltwater the fish got soft and mushy.
Finally they found a solution. They placed catfish in the tanks. Catfish are a natural enemy of codfish, so the catfish would chase them around the tanks all the time they were being transported. The cod now arrived in better condition than ever.
Relating this story, Chuck Swindoll points out that we all need catfish in our lives – the difficult people or situations in life that may not be pleasant but keep us healthy and growing.