John Erskine was the leading evangelical in the Church of Scotland in the latter half of the eighteenth century. Educated in an enlightened setting at Edinburgh University, he learned to appreciate the epistemology of John Locke and other empiricists alongside key Scottish Enlightenment figures such as his ecclesiastical rival, William Robertson. Although groomed to follow in his father's footsteps as a lawyer, Erskine changed career paths in order to become a minister of the Kirk. He was deeply moved by the endemic revivals in the west of Scotland and determined that his contribution to the burgeoning evangelical movement on both sides of the Atlantic would be much greater as a clergyman than a lawyer. Yet Erskine was no "enthusiast." He integrated the style and moral teachings of the Moderate Enlightenment into his discourses and posited new theories on traditional views of Calvinism in his theological treatises. Erskine's thought never transgressed the boundaries of orthodoxy; his goal was to update evangelicalism with the new style and techniques of the age without sacrificing the gospel message.
While widely recognized as an able preacher and theologian, Erskine's primary contribution to evangelicalism was as a disseminator. He sent correspondents like the New England pastor Jonathan Edwards countless religious and philosophical works so that he and others could learn about current ideas, update their writings, and provide an apologetic against perceived heretical authors. Erskine also was crucial in the publishing of books and pamphlets by some of the best evangelical theologians in America and Britain. Within his lifetime, Erskine's main contribution was as a propagator of an enlightened form of evangelicalism.