I am no athlete or risk-taker. I don’t jump off things, overwork my joints or engage in nearly any activity that carries a significant potential for danger.

So when I found myself having knee surgery in August (not an injury, just messed up cartilage and a benign tumor), I knew this was no mere coincidence or consequence. God had a few lessons in store for me. It wasn’t the surgery itself that helped me grow, however. It was months of physical therapy that taught...