It is difficult to compare the "Gospel of Wealth" and especially the ideology of Social Darwinism with the ideas of John Winthrop. Winthrop was a man of a very different time and place than the late nineteenth and early twentieth centuries. One possible valid comparison would be that Winthrop, a successful and comfortable English lawyer before becoming a founder of the Massachusetts Bay Colony, was, like many of his contemporaries, immersed in a set of beliefs sometimes known as the "Puritan ethic". First described by sociologist Max Weber, this set of beliefs emphasized the pursuit of wealth as a perfectly valid way to fulfill one's divine "calling," or mission in life. In short, one could honor God by being very good at one's job and by making a lot of money. However, Puritans discouraged the open flaunting of wealth, so they tended to put their money back into their businesses as capital instead of spending it on finery. Winthrop spent much of his money in founding the Massachusetts Bay Company, which sponsored the planting of the colony by that name.
Carnegie also viewed the acquisition of wealth as a sort of divine calling, and, like Social Darwinists, believed that he ought to be allowed to do so more or less free from government regulation. He had no problem with spending money on massive homes and other material things, but one of the reasons he was so powerful and successful was that he continually invested heavily in the infrastructure that supported his steel empire. He also believed that, having amassed considerable wealth, it was one's duty to society as well as to God to put it to use in a way that would benefit society as a whole. So he became a great philanthropist, endowing universities and most famously libraries with millions of dollars of his own wealth. These institutions, he thought, would help talented, motivated men like himself rise to great heights.
Social Darwinists may have appreciated the austere work ethic that underlay Carnegie's success as well as that of the Puritans, but they generally scoffed at the idea of charity, which they viewed as ultimately detrimental to mankind (it allegedly supported the weak). Their worldview was dramatically different from a seventeenth-century Puritan, and even Carnegie.