Theology is Tradition
All Protestant pastors, even the most fundamentalist, will, if they are remotely competent, prepare their sermons with the help of lexicons, commentaries, and books of theology. As soon as they take down one of these books from their bookcases and start to read it, of course, they are drawing positively on church tradition. They are not simply reading the Word of God; they are reading the thoughts and reflections on that Word offered by someone else and articulated using words, sentences, and paragraphs that are not found anywhere in the Bible. Indeed, as soon as one uses the word “Trinity” from the pulpit, one is drawing on tradition, not Scripture. In fact, tradition is not the issue; it is how one defines that tradition, and how one understands the way it connects to Scripture, which are really the points at issue.
Carl Trueman, The Creedal Imperative (Wheaton, IL: Crossway, 2012), 16