Michael Bird (also mentioned by Ari) discusses the book The Heresy of Orthodoxy: How Contemporary Culture’s Fascination with Diversity Has Reshaped Our Understanding of Early Christianity by Andreas J. Kostenberger and Michael Kruger. D. A. Carson’s endorsement of the volume is charming and worth quoting: “In the beginning was Diversity. And the Diversity was with God, and the Diversity was God. Without Diversity was nothing made that has been made. And it came to pass that nasty old ‘orthodoxy’ people narrowed down diversity and finally squeezed it out, dismissing it as heresy. But in the fullness of time (which is, of course, our time), Diversity rose up and smote orthodoxy hip and thigh. Now, praise be, the only heresy is orthodoxy. As widely and as unthinkingly accepted as this reconstruction is, it is historical nonsense: the emperor has no clothes.”
There is certainly a tendency in some circles to posit too much diversity too soon, as though the impact and teaching of Jesus had little unifying effect on the Christian movement that arose after him. Bird has useful comments to offer (both appreciative and critical) about the book.
Nevertheless, any discussion of this subject must do justice to the evidence of diversity found within the New Testament itself. Within the first half a century or so, we find disagreements over the Law and the inclusion of Gentiles (compare Paul with Matthew, as well as his opponents with whom he interacts more directly in his letters), Christology (compare Luke and John), atonement (compare Hebrews’ Platonic sacrificial/priesthood concepts with Paul’s emphasis on union with Christ), and other matters of both faith and practice.
On a related note, Darrell Pursiful discusses the Council of Nicaea as a theological Rorschach test. It seems that, even when it comes to attempts to bring unity to the church and its theology, diversity finds a way of emerging yet again.