In our currently English dictionaries happiness and joy are almost synonyms. Chelsea and I try to be a dictionary for these words as we contrast the two words. We read verses from the Bible to learn what Biblical joy means and how it doesn't always go with happiness.
Our definitions of the words:
Happiness: a state of feeling good based on present conditions
Joy: a state of hope based on future promises
Merriam-Webster.com Dictionary, s.v. “happiness,” accessed August 7, 2022.