What, then, does He say? "Blessed are the poor in spirit, for theirs is the kingdom of heaven."And the poor in spirit are rightly understood here, as meaning the humble and God-fearing, i.e. those who have not the spirit which puffs up. Nor ought blessedness to begin at any other point whatever, if indeed it is to attain unto the highest wisdom; "but the fear of the Lord is the beginning of wisdom"; for, on the other hand also, "pride" is entitled "the beginning of all sin." Let the proud, therefore, seek after and love the kingdoms of the earth; but "blessed are the poor in spirit, for theirs is the kingdom of heaven."
Augustine of Hippo