You don’t have to be Buddhist to be happy.
Buddhism is just a way of expressing the path to happiness, and identifying what is obstructing it. Theists and atheists also have their own ways of expressing happiness, and what is obstructing it. However, when experiencing it … there is nothing to say.
The only reason to look at this topic is because we need to differentiate between pure happiness, and self serving happiness. Pure happiness expresses unconditional love. Selfish happiness expresses desire, aversion and ignorance.
Interestingly, that very ‘self serving happiness’ – desire, aversion and ignorance – has enough manure to make this a better world, and us, enlightened! This is because the very nature of desire, aversion and ignorance is the wisdom qualities of Emptiness, Awareness and Compassion.
You won’t hear that very often 😉 !