The person who is poor in spirit is someone who realises the poverty of their worship and that they can't carry on in their own strength. To be poor in spirit is to be humble, without being beaten down, but to acknowledge your limited resources and your need of God.
As Matthew Henry once remarked: "To be poor in spirit does not mean one who is weak in spirit, but one who, looks to God alone to preserve him in the midst of his afflictions. He does not live out of his own resources, nor is he relying on his own achievements - his trust is in God."
“How blessed are the poor in spirit! for the Kingdom of Heaven is theirs." - Complete Jewish Bible
Many religious people in Jesus' day had become proud of their spiritual pedigree and accomplishments. In other words, they had become full of themselves. And the obvious result of this attitude, is that then we have no room for God. If I am 'full' of myself, there is little space for God to dwell.
"Pride makes us artificial and humility makes us real." - Thomas Merton
Living in Grace
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