Happiness, felicity, beatitude, blessedness, bliss all denote the enjoyment or pleasurable satisfaction that goes with well-being.
Happiness is the generic term applicable to almost any state of enjoyment or pleasurable satisfaction especially as based on one’s well-being, security, effective accomplishments, or satisfied wishes.
Felicity, denoting intense happiness is suited chiefly to formal expressions (as of congratulation) or dignified description.
Beatitude is supreme felicity.
Blessedness implies a feeling of being highly favored, especially by the Supreme Being, and often, a deep joy arising from the purest domestic, benevolent, or religious affections; bliss adds to blessedness a suggestion of exalted or ecstatic felicity; both blessedness and bliss, like beatitude, often refer to the joys of heaven.