“I just can’t trust anyone,” my friend said through tears. “Every time I do, they hurt me.”  Her story angered me—an ex-boyfriend, whom she really thought she could trust, had started spreading rumors about her as soon as they broke up.  Struggling to trust again after a pain-filled childhood, this betrayal seemed just one more confirmation that people could not be trusted.

I struggled to find words that would comfort. One thing I could not say was that she was wrong about how hard it is to find someone to fully trust, that most people are completely kind and trustworthy. Her…