Christianity has had a subtle and yet direct influence on the construct of modern economics thanks to the input of early modern economics philosophers and thinkers who were either officials in some Christian hierarchy or were devout followers of one of the religion's many sects. That influence stems primarily from thinkers during the European enlightenment. However, there were earlier thinkers who articulated some sort of doctrine of economic principles of ethical standards for economics. St. Thomas Aquinas in the 13th century was a tremendous proponent of what he called the "just price" for an item. Coming down on price fluctuations, he argued it would be unethical to charge any extra amount on an item unless there had been labor involved in it. Hence the raising of prices because of a rise in demand he felt violated the golden rule of religion (treat one another equally) and was illegitimate. His work was included in the Summa Theologica, an extensive theological compendium. His views were commented on by the Cardinal Tommaso de Cajetan in the 16th century, who also developed theories about the real price and market price of goods plus the idea that determination of the value of an item is more often than not subjective. According to Samuel Gregg, these thinkers are considered to have had a generally more positive view on material trade and the economic system that revolved around it than did the earlier Greek classical philosophers. Gregg continues to expand on the history of Christian involvement in economics by mentioning that even later secular thinkers who may have appeared to be uninvolved with, or personally distanced themselves, from Christianity either separated religion from their economic work or were more devout than would seem. This includes Adam Smith who later became a pillar of the Scottish enlightenment. In Scotland, the influence of religion is possible, taking into account the religious backgrounds and non-ideological nature of many Scottish thinkers. Hugh Blair and William Robertson are often mentioned as pillars of the Scottish enlightenment who also offered theories on economics that they did not consider to be in contravention of their faith's doctrines. In fact, they promoted a "development of commercially market-orientated societies."
On the other hand, the development of modern economic theory corresponded to a period of major changes in religious activity -- the decline of adherence to a single Church, religion in general, or a sprawl of different congregations. While many were devout, a liberal strain of political thought, which had its roots around the event of the Peace of Westphalia, went far into the future. The political theory of John Locke is said to have been born out of his upbringing as a Calvinist. The Founding Fathers of the United States are understood to have been millenarian in some of their beliefs and saw the United States as the culmination of a new promised land. John Locke also promoted the use of real value items, like gold and silver, to stand as monetary currency and not paper notes. Locke's views are evident in the development of so-called Christian Economic theory, an ideology forwarded by an evangelist Christian movement and the Institute for Christian Economics. A major proponent of this view is Gary North, a Christian Reconstructionist active in the United States.
Along with other orthodox movements, Marxism and communism was opposed by many Christians due to its undermining of private property. However, there have been several communitarian movements in Christianity whose remnants have been sympathetic to communist and socialist policies based on the idea of equality. One movement which survives is the communitarian Anabaptist sect. Unsuccessful in imposing its beliefs on Westphalia in the 16th century, its breakaway movements include the Amish and the Mennonites, both of whom made it to the Americas in large numbers. Additionally, the Puritans of New England are said to have been heavily influenced by Anabaptist thought. The original movement can be seen as a populist movement which influenced several rebellions in Germany.
In the 20th century, there was heavy opposition from the Catholic Church to the anti-religious policies of the Soviet Union. At the same time many Latin American Catholics were influenced by Liberation Theology, a doctrine later consolidated in the ideas of Gustavo Gutierrez. The concept developed in response to perceived social, political and economic injustices in Latin America. Many of the ideas expressed by its leaders, Gutierrez included, mandate the fighting of poverty and the exorcising of sin which causes it. Pope John Paul II was opposed to the mixing of Catholicism with liberal economic, even revolutionary, politics. However, he made many efforts to acknowledge the injustice of class disparity and the cycle of poverty that uneven distribution of wealth can cause.