"God only gives you what you can handle."
"What doesn't kill you makes you stronger."
When we are in the midst of vulnerability, a life challenge of any sort, it can be tough to appreciate the "makes me stronger" part. But our mental, emotional and spiritual "muscles" need to be worked just as our physical muscles do.
I am currently having physical therapy for my left shoulder. A large part of the process is to strengthen the muscles around my shoulder in order to alleviate the muscle inflammation, stress and discomfort. My damaged shoulder--vulnerability--is offering me the opportunity for greater strength.
The ultimate example in my life of Freud's quote is the vulnerability of addiction. That led me decades ago to seek help. Working the 12-step program has given me strength that I could never have dreamed of back in my using days.
Hindsight can help us appreciate our vulnerabilities more.