Quite a bit, it turns out.
The second century was a time when Christianity was challenged by many philosophies and religions. Because of this volatility, Michael Kruger, in his wonderfully conceived overview of the second century, convincingly shows that it has much to say to our own situation today.
Kruger’s book fits a huge need as the second century has been largely ignored.
Among other things, this was the time when key defenders of the Christian faith arose to give articulate and persuasive arguments.
Kruger’s book also does a terrific job of showing that the canon was largely determined far in advance of Nicea.
Kruger is thorough without being pedantic. He is a skillful scholar who knows how to write clearly.