Before I start this review, it needs to be pointed out that there are really two books here. One is the Didache itself, and the other is a book about the Didache. For purposes of clarity, I will refer to the former as the Didache and to the latter as O'Loughlin's book.
For some reason, which I cannot fathom, the Didache itself is put at the very back of the volume, making it look more like an appendix. So I was forced to read the ending before I could start on the introduction. It is a modern English translation which is perfectly understandable and doesn't take long to get through, as it is only 10 pages long.
For those of you have not come across this before, the Didache is a sort of handbook for new christians. Much of it will already be familiar, as some of the text is taken straight from the canonical gospels. It is not regarded as part of scriptural canon by the majority of christians, though it is a useful insight into how the early christian communities lived. From a reading of it, it is clear that it doesn't have the theological richness which we would associate with the books we find in our modern Bibles.
So having read the text that is to be analysed, we move onto O'Loughlin's book. He starts with the story of how it was rediscovered in the 19th century, having been lost for over 1,000 years and the only way we knew about its existence was a few references in other writings from the first few centuries of christianity.
Now while O'Loughlin does, at a few occasions, try to write with an even-handedness, his own theology and interpretation does break through, and this does sour the book somewhat. For example, while the idea of the Two Ways is a dominant theme in the Didache, O'Loughlin chooses to skip over much of this and spends a disproportionate amount of time in the book talking about the Eucharist, or communion, as most christians call it. This shows us that he takes a particularly Roman Catholic stance, and this is evidenced elsewhere by his use of other non-canonical texts as being equally authoritative as the Bible, with no delineation point discernible.
O'Loughlin's lack of rigorous scholarship shows itself as he also advocates a few minority views and misrepresents the weight attached to these views. For example, while the gospel with the Didache is most closely paralleled is Matthew, there is some debate as to which came first: Matthew or the Didache. O'Loughlin takes the stance that it was probably the Didache which was written first, or at least that they were written at the same time. He also appears to subscribe to the ideas of the Jesus Seminar, where at one point he refers to Matthew putting words in Jesus' mouth, seemingly dismissive of the idea that the author of Matthew might have actually been recording words that Jesus said. This lazy scholarship does mar the book somewhat, and I was surprised to see it got passed the editorial board of SPCK (the publishers) who normally have such a high standard.
So with that aside, we have try and read O'Loughlin's book through the distortions, much like trying to do ground-based astronomy, counteracting atmospheric disturbances. What we end up with is a very low-level introduction to early christianity for those who may look at the modern strands of christendom and think that one modern denominational church basis itself on the early christians. In this manner, O'Loughlin seems to be having a go at some Catholics, where phrases are banded about such as “one true church” or who still propound the myth that Peter was the first pope (in spite of the fact that the earliest evidence for anything resembling a papacy didn't emerge until the 6th century).
As to the date of the Didache, it seems to have not been in widespread circulation until at least the end of the first century or perhaps even the early 2nd century. No single or small group of authors is ever identified, and the Didache does seem to be a compilation derived from several sources. One of these may be the gospel of Matthew (or at the very least, the same oral tradition of which Matthew's gospel is the written form) but also of the practices that the early christians had adopted and were looking to turn into traditions. So the Didache is much more a forerunner of modern “lifestyle christianity” books than theology, and this is why I think it is worth reading, but when measured alongside the rest of the New Testament, it falls short of the level of depth that we see elsewhere.
There are plenty of other books that put across the history of the early church much better than O'Loughlin does, and where the Didache is considered in the context of other non-canonical writings of around the same period. So I would recommend anyone read the Didache, which can be done online, though there are plenty of better books on the early church than that written by O'Loughlin.