moish-
If a person has emunah- the real thing, deep down- they feel Hashem’s love through everything, even when someone close is niftar; and they can clearly see it is for everyone’s good. Emunah= inner peace= happiness. Happiness is not dancing and a smile on your face (although at times that is part of it)
Unfortunately I do not have experience in this and did not yet come to such a level, but I believe this is how it is ultimately supposed to be.
Correct me if I’m wrong (hashkafah wise)