On Living Simply
The rich usually imagine that, if they do not physically rob the poor, they are committing no sin. But the sin of the rich consists in not sharing their wealth with the poor. In fact, the rich person who keeps all his wealth for himself is committing a form of robbery. The reason is that in truth all wealth comes from God, and so belongs to everyone equally. The proof of this is all around us. Look at the succulent fruits which the trees and the bushes produce. Look at the fertile soil which yields each year such an abundant harvest. Look at the sweet grapes on the vines, which gives us wine to drink. The rich may claim that they own many fields in which fruits and grain grow; but it is God who causes seeds to sprout and mature. The duty of the rich is to share the harvest of their fields with all who work in them and with all in need.
On Living Simply II
We do not need to buy air, water, fire, sunshine and things of this kind. God has given enough of all these blessings for everyone to enjoy them freely. The sun shines equally on the rich and the poor, and they both breathe the same air. Why is it, then, that these necessary things, which sustain life, are created by God for common use, while money is not common? The reason is twofold: to safeguard life and to open the path to virtue. On the one hand if the necessities of life were not common, the rich, with their usual greediness, would take them away from the poor. In fact, since they keep all money for themselves, they would certainly do the same with these necessities. On the other hand if money were common and available to all, there would be no opportunity for generosity on the part of the rich and gratitude on the part of the poor.