Why do we attach such value to material things, seeing that we have been taught to despise them? Why do we cling to money and possessions, and disperse our intellect among a host of useless cares? Our preoccupation with such things diverts us from what is more important and makes us neglect the well-being of the soul, leading us to perdition...
For the true philosopher possessions are superfluous, since he detaches himself from bodily concerns for the sake of the souls purity... Indeed, is it ever right to engage in disputes in order to protect our property?
...Why do we try to make other people’s property our own, weighing ourselves down with material fetters, and paying no attention to the prophet’s imprecation: ‘Woe to him who gathers what is not his own, and heavily loads his yoke’ (cf. Hab. 2:6. LXX). Those who pursue us are, as Jeremiah says, ‘swifter than the eagles of heaven’ (Lam. 4:19); but we weigh ourselves down with worldly things, move slowly along the road and so are easily overtaken by our pursuer, covetousness, which Paul taught us to flee (cf. Col. 3:5)...
Attachment to worldly things is a great obstacle to those who are striving after holiness, and often brings ruin to both soul and body...
So possessions arouse feelings of jealousy against their owners, cut off their owners from men better than themselves, divide families, and make friends hate one another. Possessions, moreover, have no place in the life to come, and even in this present life have no great use... Human efforts inevitably fail unless God helps us; while God in His providence bestows every blessing without man’s assistance.
Philokalia, Vol. 1 - pages 206-7