Unlike the interpretations of some scholars, John Wesley did not have a fundamentalist world view, in which faith ignores or isolates scientific truth, as most revivalists are thought to have. Wesley tried to learn, understand, and use newly introduced scientific knowledge, information, and development. He was so eager to inform his followers of scientific truth as to write his own Compendium of Natural Philosophy, and revised and published it several times. Wesley was more familiar with the term natural philosophy rather than natural science, and he thought he was doing philosophy as universal knowledge. It is, however, hard to say that Wesley was simply an advocate of scientism. Wesley accepted scientific realities in the world, and he thought that the task of science is to describe the measurable and experimental facts and their processes and history. Wesley expected that the original intents and goals of the facts would be answerable by theology. In this sense, Wesley pointed out that the spot to answer all questions beyond science is the starting point of theology. In his thought, science and theology are well balanced, harmonized, and helpful for each other. Firstly, Wesley argued that science is the ground of theology, and the basis of theology. He believed that knowledge of the natural world leads people to faith in and study of God, the Creator and the Provider. On the basis of science, Wesley expected to begin the theology of creation and providence. He did not try to explain the nooks and crannies of facts with the verses from the Bible, because he thought that the mystery and awe is also part of science. He had such an optimistic view of science that he published a book of medical treatments for his preachers. Secondly, for Wesley science could be a ground in his eschatology. Especially, that the old Wesley was interested in natural science shows his expectation for the future, the new heaven and earth, and preparation for his own death. All the things which are mysteries and puzzle us now, believed Wesley, will be explained, understood, and solved in the end. Finally, Wesley’s science implied ethical requirements. As a minister, he tried to persuade his people to be “stewards” keeping the created world and restoring the corrupted parts with God’s grace. Wesley himself got involved in such issues as slavery, education, and female participation in ministry. In this sense, his theology as well as science showed somewhat radical and advanced aspects which some contemporary readers might be hesitant to follow.