Deists (from the Latin Deus ‘God’) argue that reason and not revelation provides the basis for belief in God. There were many different forms of Deism so any summary will not apply to all Deists however, most argued that God created the world using rational and logical processes and they presented God as the master mathematician and the supreme scientist. Many believed Christianity to be corrupt and they wanted to return to what they termed ‘natural religion’ based on reason and morality. Deists believed that if God designed the world by creating the laws of nature then by studying the processes of science human beings could understand something of the mind of God. The American Deist Thomas Paine said
Isaac Newton also believed that the natural world provided evidence for God.
Obviously the idea that creation revealed the creator was already found within Christianity and is based on the idea of general revelation. During the post-Enlightenment period mainstream Christianity showed great interest in Natural Theology as a way of gaining knowledge of God. It was during the eighteenth century that William Paley set out his teleological argument (design argument) for God’s existence. However, mainstream Christianity used reason in addition to special revelation whereas the Deists rejected revelation entirely.
This meant that Deism differs significantly from traditional Christian theology. The Deists rejected the idea of a God who intervenes in human affairs and they reject special revelation as a source of knowledge for God. Thus they reject the concept of the incarnation and the idea of the Bible as a source of divine wisdom. Furthermore, a Deistic outlook is generally thought to ruled out the possibility of miracles and made supplicatory prayer (asking for things) pointless.
Consequently, although the existence of Deism shows that post-Enlightenment modes of thought need not lead to atheism, Deism itself constitutes a significant challenge to Christianity.