Does confessing the Christian faith and saying openly that you believe the creed make you a Christian? The simple answer, of course, is no. But I urge you to think about this question differently. The question is not: "How much do I have to understand and believe to be saved?" The question must be framed by a text like Romans 10:9-10 it seems to me. Here the apostle makes it abundantly plain that what you believe and confess is a matter of being "justified" and "saved." As one popular comic puts it, "Not too fast my friend, not too fast." Maybe creeds and confessions are somehow vital to living faith.
The famous Augustine of Hippo, in quoting from a variety of Western creeds in various forms, opens one of his earliest written works, On Faith and the Creed, with the assertion that "we cannot secure our salvation unless . . . we make our own profession of the faith that we carry in our heart. . . . . We have the catholic faith in the creed, known to the faithful and committed to memory, contained in the form of expression as concise as has been rendered admissible by the circumstances" (cited by Pelikan in Credo, 36).
Augustine goes so far as to define faith as "thinking with assent (cum assensione cogitare)" (cited in On the Predestination of the Saints). And Rufinus of Aquileia, in his ancient commentary on The Apostles' Creed says that saying "I believe" means that "it is only right that you should first of all confess that you believe."
You might argue that this approach was true in the West but perhaps not in the East. If you did you would be wrong. In Peter Mogila's book, The Orthodox Confession of the Catholic and Apostolic Eastern Church, the author quotes the words of Paul in Romans 10 to introduce the creed itself. And when we come to the Protestant Reformation the same is true with Lutheran confessions. Here we see an extensive discussion of the relationship between living faith and confessing the faith. And on the Reformed side it is no different.
Pelikan concludes that "believing and confessing have always been correlatives" (Credo, 37). He notes that a creed-like confession in the New Testament is plainly followed by the formula, "So we preach and so you believed" (1 Cor. 15:3-11). The reality becomes very clear, adds Pelikan, when you see how the terms believe and confess are so closely linked with the word teach in the New Testament itself.
Here is my simple conclusion. We are not saved by saying right words or by reciting a creed. We are saved by Christ. But the Christ who saves us is not just any Christ, the "Christ of faith" or "the Christ in my heart." He is the Christ of history and apostolic teaching. Put in a historic and accurate way he is the Christ of Nicea and Chalcedon or he is "another" Christ, not the Christ of the Christian Church and the biblical record. Indeed this was so important to the early church that the first use of anathema in the written record came when they dealt with those who would not confess what these early creeds said about God and Jesus.