Often we see a situation, and we understand what must be done. We see what could be done better. But it's a lot easier to talk than act, isn't it?
That's what our reading is about.
Walk the talk is a saying we have in English. If you walk the talk, your beliefs go beyond words. Your actions speak for themselves.
You can challenge someone to walk the talk if they aren't keeping a promise or if they're telling others to do something, but they aren't doing it themselves.