Being "poor in spirit" is about an attitude. It is a heart-thing. It's related to humility.
I was praying this verse last night, and God told me: "Diminish." Become less, so that God can become more.
Craig Evans writes: "The opposite of the poor in spirit are "violent men" who try to take the kingdom of heaven by force (Matthew 11:12), men who will not humble themselves and become like children (Matthew 18:3; 19:14)." (Craig Evans, Matthew, 104)
I am to get small, so God can loom large.
Craig Keener says "["poor in spirit"] refers not merely to the materially poor and oppressed, but to those who have "taken that condition to their very heart, by not allowing themselves to be deceived by the attraction of wealth" (quoting Sean Freyne, Galilee, Jesus and the Gospels: Literary Approaches and Historical Investigations, p. 72). Although Matthew does not stress renunciation of possessions to the same degree as Luke, for him as well the kingdom belongs to the powerless of the world, to the oppressed who embrace the poverty of their condition by trusting in God rather than favors from the powerful for their deliverance." (Craig Keener, The Gospel of Matthew: A Socio-Rhetorical Commentary, 169)
I am to get less, get simple, so God can show his beauty.
Michael Wilkins writes:
"The kingdom of God belongs to those who know they have no resources, material or spiritual, to help themselves before God. These are the "poor" to whom Jesus has come to announce "good news" (Matt. 11:5) and to whom the kingdom belongs." (Michael J. Wilkins, The NV Application Commentary: Matthew, 206)
In my spiritual poverty I am blessed, for God rules and reigns over me.