To live happily is an inward power of the soul.
Just like a common language is the key to communication of knowledge, a common faith is the key to living happily in a group as a family or friends.
I've already had my happily ever after.
It is not necessary that whilst I live I live happily; but it is necessary that so long as I live I should live honourably.
I don't sleep with happily married men.