“Blessed are the poor in spirit, for theirs is the kingdom of heaven.” (Matthew 5:3, ESV)

The word that the ESV translates as “blessed” is the Greek word μακάριος .  Louw-Nida defines the word as: “pertaining to being happy, with the implication of enjoying favorable circumstances—‘happy.’”

The Theological Lexicon of the New Testament (TLNT) has a good discussion of the word μακάριος . It explains that “blessed”  “is much more than contentment; it is an interior joy that becomes external, elation translated into shouts, songs, acclamations. The explanation is that God will be the source of this beatitude.”

TLNT goes on to say:

the new faith implies a reversal of all human values; happiness is no longer attached to wealth, to having enough, to a good reputation, power, possession of the goods of this world, but to poverty alone, because these beatitudes envision one or another aspect of the ptochoi of the OT.29 These are essentially religious souls, in submission to God’s law, obedient to his will. God is their only recourse and their only hope, and they are entirely ready to accept his gifts. They are profoundly humble, modest, unassuming, the “little ones” who are not taken into account and who possess nothing on earth; they are starving and weeping. More than scorned, they are exploited by the powerful and the rich, who prey on them, oppress them, and persecute them. It is to these afflicted ones that the Holy Spirit promises happiness, consolation, and satisfaction.

When we come to understand that God is the source of our hope, of our wealth, of our contentment, and of our joy in life, then we will begin to have an inkling what it means to be truly happy.  It is only then that we can understand what it means to be blessed. [μακάριος]