"Thou shalt not steal"

The duties required in the eighth commandment are,
- truth, faithfulness, and justice in contracts and commerce between man and man;
-rendering to every one his due;
-restitution of goods unlawfully detained from the right owners thereof;
-giving and lending freely, according to our abilities, and the necessities of others;
-moderation of our judgments, wills and affections, concerning worldly goods;
-a provident care and study to get, keep, use, and dispose these things which are necessary and convenient for the sustenation of our nature, and suitable to our condition;
-frugality;
-avoiding unnecessary law-suits, and suretiship, or other like engagements;
-and an endeavor, by all just and lawful means, to procure, preserve, and further the wealth and outward estate of others, as well as our own. (taken from the Larger Catechism of the Presbyterian Church - Answer to Question 141)

The sins forbidden in the eighth commandment, besides the neglect of the duties required, are
-theft, robbery, man-stealing, and receiving any thing that is stolen;
-fraudulent dealing, false weights and measures, removing landmarks, injustice and unfaithfulness in contracts between man and man, or in matters of trust;
-oppression, extortion, usury, bribery, vexatious lawsuits, unjust inclosures and depredation;
-engrossing commodities to enhance the price, unlawful callings, and all other unjust or sinful ways of taking or withholding from our neighbor what belongs to him, or of enriching ourselves;
-covetousness;
-inordinate prizing and affecting worldly goods;
-distrustful and distracting cares;
-envying at the prosperity of others;
-as likewise idleness, prodigality, wasteful gaming, and all other ways whereby we do unduly prejudice our own outward estate;
-and defrauding ourselves of the due use and comfort of that estate which God hath given us. (taken from the Larger Catechism of the Presbyterian Church - Answer to Question 142)

"And he said to them, "Beware, and be on your guard against every form of greed; for not even when one has an abundance does his life consist of his possessions."  (Luke 12:15)