One of my close friends tells of his first introduction to the Reformed faith. A week after his father’s funeral he ran into a man who attended a local Reformed church. During the course of the discussion my friend expressed sorrow over the fact that his father was not a believer. Immediately the man responded, “Well he must not have been one of God’s elect.” You can only imagine the anger. This is a sad but real commentary on how Reformed people are often represented or even represent their faith.
The Reformed faith is based on a certain knowledge and conviction that everything that God has revealed in His Word is true (Heidelberg Catechism Q&A 21). The catechism connects this knowledge with a deep-rooted assurance in the gospel promises. When these elements are present, this certain knowledge and trust expresses itself visibly as the church unites together in what is confessed. The accuracy of the Reformed faith, therefore, is determined by this certain knowledge; a collective body of truths upon which their derivation is from Scripture and are confessed by those who walk together in unity.
To define the Reformed faith in the worst sort of way, would be to lift-up one doctrine as the grid through which the whole body of truth is defined. Again, this if often done with the doctrine of predestination. To define the Reformed faith in the most irresponsible sort of way, would be to pick and choose what I like, disregard what I don't, and then claim the patent on the label. This is often done today, ironically, by many in the Emergent Church movement or by those who reject infant baptism--among other things. There are, of course, certain doctrines that function as organizing principles of the Reformed faith, (the doctrine of the covenants is often viewed as the fundamental organizing principle of the Reformed faith) but to speak of certain doctrines as central or organizing to the whole is quite a different thing than to pick and choose what I like and still claim Reformed.
Further, the question itself, “What does it mean to be Reformed?", suggests that the Reformed body of doctrine runs contrary to something else. For the Reformers of the 16th and 17th centuries, these contrary systems of doctrine were Roman Catholicism and Arminianism, respectively. While the same is true for Reformed Christians today, movements such as Christian liberalism, the Emergent Church, and the continuing saga of Evangelicalism, have, with new rubric, attacked much of the certain knowledge that has historically defined what it means to be Reformed. The same perennial fight remains.
The difference in our day, however, comes to us in an evangelical climate that has devalued particulars. In other words, there is nothing that really defines Evangelicalism. And if people are searching for substance, the labels seem to no longer matter, or are at the least, depreciated. The outcome has been predictable. People are finding some of the particulars in the Reformed faith appealing. Here they have found stability and content, something "new". Reformed, therefore, seems to have become a house of refuge for those certain evangelicals who are burnt-out and looking for meaning through particulars--albeit, particulars they feel, in good Biblicist fashion, they get to choose for themselves. This has created a melting pot so that much of what passes for Reformed is drastically reductionistic and assimilated to the above named movements. I raise this simply to say that this poses a significant challenge for those historic Reformed Christians who hold to a certain knowledge in what they confess. For one to even begin to accurately define Reformed, there must be an appreciation for the particular historical moment Reformed Protestantism gave birth and, subsequently, the tradition by which it was shaped.
Taking these things into consideration, a Reformed Christian is required to adhere to the infallible, inerrant Word of God and align himself to that whole body of doctrine that has its roots in the Protestant Reformation. The Reformed confessions, preeminently the Belgic Confession (1561), the Heidelberg Catechism (1563), the Canons of Dordt (1619) and the Westminster Standards (1647), find their roots in historic Protestantism, and provide for us this body of doctrine that define the boundaries by which Reformed is to be defined. Thus a Reformed person is one who is a confessional, Bible-believing Christian who has his feet firmly planted in the historic Protestant tradition. Under this basic definition of Reformed stand a variety of different ethos and motifs that help to define the grandness of the Reformed faith (as Machen called it) living in the twenty-first century.