The Pope is actually accurate here.
Go back and read Abraham’s haggling with God.
There’s a history of kvetching (complaining) in Jewish tradition, including in their interactions with God.
Was there any hint of complaint in “Remove this cup from before me if possible.” Obviously Christ then said, “Let Thy will be done.”
Did Job complain?
Sure hope the Pope is right about this, since I’ve done a fair share if kvetching to God about Pope Francis!
Moses did his fair share of complaining too when he was leading the Israelites through the desert. Life is hard and God can handle all of our emotions. I agree with the Pope on that issue, but letting bitterness take root is not wise nor is it wise to encourage others to do so.