With the increase of wealth the mania of covetousness increases. - John Cassian

Our third conflict is against covetousness which we can describe as the love of money; a foreign warfare, and one outside of our nature. ... For the rest of the incitements to sin planted in human nature seem to have their commencement as it were congenital with us, and somehow being deeply rooted in our flesh, and almost cœval with our birth, anticipate our powers of discerning good and evil, and although in very early days they attack a man, yet they are overcome with a long struggle. But this disease coming upon us at a later period, and approaching the soul from without, as it can be the more easily guarded against and resisted, so, if it is disregarded and once allowed to gain an entrance into the heart, is the more dangerous to every one, and with the greater difficulty expelled. For it becomes "a root of all evils" [1 Timothy 6:10] and gives rise to a multiplicity of incitements to sin.

We must not only guard against the possession of money, but also must expel from our souls the desire for it. For we should not so much avoid the results of covetousness, as cut off by the roots all disposition towards it. For it will do no good not to possess money, if there exists in us the desire for getting it.

Yet sometimes the mind which advances to that true disposition of purity and has already begun to be rooted in it, conceiving all of these at one and the same time and rushing through them all like a kind of ungraspable and devouring flame, pours out to God wordless prayers of the purest vigor. These the Spirit itself makes to God as it intervenes with unutterable groans, unbeknownst to us, conceiving at that moment and pouring forth in wordless prayer such great things that they not only—I would say— cannot pass through the mouth but are unable even to be remembered by the mind later on.