I recommend Doug Sweeney's recent book [Jonathan] Edwards the Exegete (Oxford University Press, 2015), which is a terrific treatment of the way in which Edwards was steeped in the Bible, so that it shaped the whole of his thinking.

We are still living with the consequences of that today in popular Reformed thinking from the likes of John Piper, R. C. Sproul, and Tim Keller.

Now, don't get me wrong: I'm not rubbishing penal substitution. But there are other options that have been advocated by Reformed thinkers of the past.

Sometimes we can lose the wood for the trees. Some specific issues dealt with in the book [Saving Calvinism]: the scope of election (who is saved?); the nature of the atonement (do we have to hold to penal substitution if we're Reformed?); the scope of the atonement (for whom did Christ die?); whether we have to hold to some sort of theological determinism (God ordains all that comes to pass).

For those who have only ever read about [John] Calvin, reading the man himself is an invigorating experience.

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.

I think everyone who has an interest in Reformed theology, or just in Christian theology more generally, should read John Calvin Institutes.