"Rabbi Elazar of Bartota says: Give Him from that which is His, for you and yours are his. Similarly, King David said: ‘For everything is from You and from Your hand we have given to You.’ " [Avot 3:7, I Chron. 29:14]

...whatever one owns in this world is from G‑d.

The meaning of the phrase "Give Him from that which is His" is that whatever one owns in this world is from G‑d. Thus, the Sage tells us to "give Him," G‑d, "from that which is His, for you and yours are His," meaning that all of the wealth that G‑d bestows upon the wealthy is only considered a "deposit"; the wealthy are merely considered the "guardians" of G‑d’s possessions, in order for them to be able to assist the needy and the downtrodden. As a result, they are indeed worthy of living a life of affluence.

This can be explained with a very interesting law regarding one who departs from this world and leaves over a will in which he bequeaths all of his possessions to one of his sons as a gift: "If one writes [a will leaving] all of his possessions as a gift for one of his sons, he [effectively] has only made him a guardian, and [therefore] he inherits the possessions equally among the rest of his brothers." (Shulchan Aruch Choshen Mishpat ch. 246)

This means that although the father has written in his will that he is leaving his whole estate to only one of his sons, we do not rule that this son is the sole inheritor, for we assume that the father did not intend to remove the rights of his other sons to his possessions. Rather, he only meant for his other sons to respect this particular son and to heed his instructions as to the division of the inheritance. Thus, this particular son is indeed responsible for the financial aspects of the inheritance, yet he only collects a share of the inheritance which is equal to that of his other brothers.

...this particular Jew...is only considered a guardian appointed to divide it among his needy brethren...

Similarly, when G‑d showers wealth upon one of his sons among the Jewish nation, this particular Jew is not considered to be the owner of this wealth. Rather, he is only considered a guardian appointed to divide it among his needy brethren in order to support them. Due of this, he is indeed worthy of honor. That is why Rabbi Yehuda HaNassi and Rabbi Akiva would respect wealthy individuals. (Eruvin 86a) Clearly, this refers to wealthy individuals who feared Heaven and performed kindness and charity.

The Sefer Chassidim states that there are certain situations when a certain individual may not really be so deserving of life, but he will continue to live because others depend on him. If he were to stop helping others, he would immediately depart from this world. Similarly, at times when one sins before G‑d, so that he is deserving of all sorts of harsh illnesses and the like, nevertheless G‑d does not punish this person because others depend on him. Thus, the merit of the public protects him and this will in turn facilitate him with the opportunity to repent and mend that which he has broken.

[From http://www.halachayomit.co.il]