What truly makes you stronger is not persistence, but letting go.
真正让你变强的不是坚持，而是放手。
该句使用what引导的主语从句与not...but...并列结构，通过对比强调了“放手”而非“坚持”才是力量的源泉。
"If you truly desire something, let it go; if it returns, it is forever yours."
"There are many forms of love in the world, but only letting go represents the highest state of love."
"When a relationship ends, let it go and accept it."
"some people require letting go rather than persistence"
"The more you crave possession, the more you need to learn to let go."