The concept of happiness according to classical authors:
Aristotle begins his work with his book "About the soul", in which he explains that the soul is the perfection of the body and the first mobile motor. From then all his books are developed from this study of the soul. In Nicomaquean Ethics he affirm: "happiness is a certain activity of the soul", "happiness is the most perfect good", "happiness is the reward of virtue", then in Rhetoric says: "happiness is the wellness accompanied by virtue".
Thomas Aquinas, father of the scholastic school, start his studies with God, not from the soul and affirms in the Summa Theologica: "God is the happiness of man", "eternal happiness consists in the vision of God", "the happiness is what everyone wants unanimously". The scholastic philosophy places happiness in relation with God and fundamentally in the contemplation of God.
In the Bible the ecclesiastes teach to us: "Happiness is for those who fear God". The old testament lays happiness in the hands of the devotees, remember that the fear of God as a spiritual gift is devotion.
In the New Testament, in the Gospels of Luke and Matthew, Christ focus his teachings on the Beatitudes and places happiness in the hope of the blessed life and the realization of the kingdom of God.
The concepts of happiness are many and vary, according to the differents classic authors. Each reader chooses with which concept of happiness stays.