The book [Saving Calvinism] argues in each case that the Reformed tradition is broader and deeper than we might think at first glance - not that there are people on the margins of the tradition saying crazy things we should pay attention to, but rather that there are resources within the "mainstream" so to speak, which give us reason to think that the tradition is nowhere near as doctrinally narrow as the so-called "Five Points of Calvinism" might lead one to believe.

For instance, the notion of non-penal substitution. This idea, found in the work of the nineteenth century Scottish Reformed theologian John McLeod Campbell and based upon his reading of the letter to the Hebrews in particular, is that Christ offers up his life and death as a penitential act on our behalf, rather than as a punishment in our stead.

Here is the interesting twist:[McLeod] Campbell came to his views through reading Jonathan Edwards who suggested at one point in his ruminations on the atonement that Christ could have offered up a perfect act of penitence instead of punishment, and that this would have been an acceptable offering suitable to remit our sinfulness.

[John] Calvin's Institutes is often called a summary of Christian piety. You can't say that about many modern works of theology. You can say it of Calvin.

God shows us in Christ what he would have to do if he were to punish us for our sins.

In the twentieth century the Reformed tradition was developed in several ways including additional confessions (Barmen, the Belhar Confession, the 1967 Confession of the PC(USA), and so on). It was also significantly augmented by the work of important thinkers like Karl Barth, T. F. Torrance, Jürgen Moltmann, Emil Brunner, Kathryn Tanner, and so on.

Reformed theology belongs to this confessional tradition, and Reformed theologians and churches continue to write confessions even today.