Be on your guard in times of feeling as if you can't do anything right, when you feel as if you can't do anything right stand firm in your faith, this will help you be courageous and strong. As well as helping you do things in love even when you think that you can't.
This is how I interpret this verse.
It's like a story, that you can implant into your brain to remember how to act in times of doubt or other tough times. :)
