Former religious person here. A common analogy drawn upon is a tree. A tree that faces no hardship (bad weather, etc.) looks pretty but has little depth and can't sustain during high winds and such. The converse says that if a tree has survived hard times it probably will survive additional hard times.

It's bollocks, of course, and often pacifies folks from working to improve their own personal situations. Nietzche's religious critiques come to mind in this type of situation.