That biblical phrase was quite appropriate for the time because wealth was most often acquired through capturing, plundering and looting your fellow man. But, with the rise of capitalism, people like Bill Gates are rich because they have served their fellow man. Gates has made his fellow man very happy by building Microsoft computers and software. Fred Smith with Federal Express serves his fellow man, too. The morality of the free market should be stressed because it is far superior to any other method of allocating resources.
Morality is at the level of voluntary exchange.
But capitalism opens up a whole host of opportunities for immorality. The fact that Gates is successful in developing and selling computers does not mean he is a moral person. But he is behaving in a moral way. With regard to the market. I judge people by their behavior, whether Gates intends to make Walter Williams happy is not the issue.