The power of hope… “For we were saved in this hope, but hope that is seen is not hope; for why does one still hope for what he sees?” - Romans 8:24 (NKJV)
They were envious.
“These last men have worked only one hour, and you made them equal to us who have borne the burden and the heat of the day.”
- Matthew 20:12 (NKJV)