Matthew's version of the beatitudes, in contrast to Luke's, emphasizes the inward disposition of a person, rather than the condition of his outward circumstances. This blessedness has a this-worldly character. It is in the midst of this life and creation, a creation restored by Christ, in which this blessed state is found. While this state begins and grows in this present life, it is only fully realized in the time to come (New Century Bible Commentary: The Gospel of Matthew, 110).
The Beatitudes turn conventional wisdom upside down. I've been doing yoga for quite some time, and I have noticed that, when you stand on your head, everyone else looks like they're walking upside down. There are those who are convinced that during the "lost years" (between 12 and 30), Jesus spent some time in India. I don't know if he went there and learned to do headstands, but I do know that, in speaking the beatitudes, Jesus is speaking as if he were looking at conventional common sense upside down.
Fans of Jesus admire his idealism and spirit of sacrifice as they go their own way, a path paved by common sense and self-preservation. Blessed are the self-reliant (not the poor in spirit), the cheerful (not those who mourn), the bold (not the meek), the proactive and the ambitious (not those who hunger and thirst for righteousness), those who demand to be treated fairly (not the merciful), those with a single, driving ambition (not the pure in heart), those who stand up for themselves (not the peacemakers), those who have a high quality of life (not the persecuted), and those who have a good reputation (not those who are reviled and slandered).
Friends (i.e., followers, disciples) of Jesus take him at his word and put his upside-down beatitudes to the test. The life of discipleship is a process of shifting our status from fan to friend of Jesus in the specific scenes and situations of our daily lives. It's a risky replacement of one definition of what it means to be blessed with another.
Let's see if, when we manifest humble dependence on God's grace, God can make us contributors to the divine reign on earth (5:3).
Let's see what happens when we lament, not just our personal sorrows, but those of all who are subjected to injustice, and are moved to do something about it (5:4).
Let's see what happens when we embrace meekness, not as passivity, but as proactive humility that is a key ingredient of leadership (5:5).
Let's see what happens when we "hunger and thirst to see right prevail" (New English Bible) and put our actions behind our appetite for justice (5:6).
Let's see what happens when we embrace compassion and forgiveness, recognizing them as actions and not merely as attitudes (5:7).
Let's see what happens when we ask God continually to purify us from all inward motivations that do not spring from God (5:8).
Let's see what happens when we work for peace in the midst of people and communities in conflict (5:9).
Let's see what happens when we pray to have the heart of a lion and the skin of a rhinoceros, able to risk and withstand criticism in service of God's calling on our lives (5:10-11).
Each beatitude is like a glowing candle, waiting to light our particular path. Fans of Jesus can't be bothered to bear the light of Jesus into a hurting world. But friends are a different story.
For more reflections on the Gospel of Matthew, see Alyce McKenzie's Interpretation Bible Study Commentary on Matthew (Westminster John Knox Press, 2002).