“If, then, we keep in reserve any earthly possessions or perishable wealth, the mind sinks down as into mire and the soul inevitably becomes blind to God and insensible to the desire for the beauties of heaven and the good things laid up for us by promise…
These we cannot gain possession of unless a strong and single-minded desire leads us to ask for them and lightens the labor of their attainment. This, then, is renunciation, as our discourse defines it: the severance of the bonds of this material and transient life and freedom from human concerns whereby we render ourselves more fit to set out upon the road leading to God. It is the unhindered impulse toward the possession and enjoyment of inestimable goods…
In short, it is the transference of the human heart to a heavenly mode of life…Also–and this is the chief point–it is the first step toward the likeness of Christ, who being rich, became poor for our sake. Unless we attain to this likeness, it is impossible for us to achieve a way of life in accord with the gospel of Christ. How, indeed, can we gain either contrition of heart or humility of mind or deliverance from anger, pain, anxieties–in a word, from all the destructive movements of the soul–if we are entangled in the riches and cares of a worldly life and cling to others by affection and association?”
Basil the Great (330-379) in The Long Rules 8 ACCS 1.2C.270.