happiness
this is not a term which has been extensively used in the Christian tradition. It has been most strongly deployed within utilitarian thinking, which has promoted it as the absence of pain and the most desirable end in terms of which to weigh the rights and wrongs of particular actions. This is the measure of the ‘Felicific Calculus’. The appeal of ‘happiness’ is also pervasive in popular culture (so the theatrical: “Is everybody happy?”). Critics, however, remark that ‘right and wrong’ is a more reliable currency than being happy. Duty and self-sacrificial love may actually entail some real unhappiness. Perhaps the contrast is overplayed?
According to John’s gospel, Jesus actually uses the word ‘happy’ of the person who washes another’s feet (13:17). Two other words have related currency for Christians. One is that of ‘blessedness’ as found in ‘the Beatitudes’ (Matthew 5), and the other ‘gladness’, associated with the shared delight and vitality found in this man Jesus.