Sproul, R. C. (2016). What Is Reformed Theology?: Understanding the Basics. Grand Rapids, MI: Baker Publishing Group. стр. 36. ISBN978-0-8010-1846-6. „The Reformers called themselves evangelicals because they believed the doctrine of justification by faith alone is central and essential to [the gospel]. Since the biblical word for gospel is evangel, they used the term evangelical to assert their conviction that sola fide is [the gospel].”