Commenting of the 8th commandment, “You shall not steal.” [Ex. 20:15], Calvin says:
We must consider that what every man possesses has not come to him by mere chance but by the distribution of the supreme Lord of all. For this reason, we cannot by evil devices deprive anyone of his possessions without fraudulently setting aside God’s dispensation. Now there are many kinds of thefts. One consists in violence, when another’s goods are stolen by force and unrestrained brigandage. A second kind consists in malicious deceit, when they are carried off through fraud. Another lies in a more concealed craftiness, when a man’s goods are snatched from him by seemingly legal means. Still another lies in flatteries, when one is cheated of his goods under the pretence of a gift.
Let us not stop too long to recount the kinds of theft. Let us remember that all those arts whereby we acquire the possessions and money of our neighbors – when such devices depart from sincere affection to a desire to cheat or in some manner to harm – are to be considered as thefts. Although such possessions may be acquired in a court action, yet God does not judge otherwise. (Calvin, Institutes, II. viii. Section 45.)
A little later:
We will duly obey this commandment, then, if content with our lot, we are zealous to make only honest and lawful gain; if we do not seek to become wealthy through injustice, nor attempt to deprive our neighbour of his goods to increase our own; if we do not strive to heap up riches cruelly wrung from the blood of others; if we do not madly scrape together from everywhere, by fair means or foul, whatever will feed our avarice or satisfy our prodigality. On the other hand, let this be our constant aim: faithfully to help all men by our counsel and aid to keep what is theirs, in so far as we can; but if we have to deal with faithless and deceitful men, let us be prepared to give up something of our own rather than to contend with them. And not this alone: but let us share the necessity of those whom we see pressed by the difficulty of affairs, assisting them in their need with our abundance. (Calvin, Institutes, II. viii. Section 46.)