Today is the feast of St. Leo the Great, Doctor of the Church. From his Sermon 95:
The nature then of Christ's teaching is attested by His own holy statements: that they who wish to arrive at eternal blessedness may understand the steps of ascent to that high happiness. Blessed, He says, are the poor in spirit, for theirs is the kingdom of heaven. It would perhaps be doubtful what poor He was speaking of, if in saying blessed are the poor He had added nothing which would explain the sort of poor: and then that poverty by itself would appear sufficient to win the kingdom of heaven which many suffer from hard and heavy necessity. But when He says blessed are the poor in spirit, He shows that the kingdom of heaven must be assigned to those who are recommended by the humility of their spirits rather than by the smallness of their means. Yet it cannot be doubted that this possession of humility is more easily acquired by the poor than the rich: for submissiveness is the companion of those that want, while loftiness of mind dwells with riches. Notwithstanding, even in many of the rich is found that spirit which uses its abundance not for the increasing of its pride but on works of kindness, and counts that for the greatest gain which it expends in the relief of others' hardships. It is given to every kind and rank of men to share in this virtue, because men may be equal in will, though unequal in fortune: and it does not matter how different they are in earthly means, who are found equal in spiritual possessions. Blessed, therefore, is poverty which is not possessed with a love of temporal things, and does not seek to be increased with the riches of the world, but is eager to amass heavenly possessions.