David Mills, in an article on Identifying Evangelicalism remarks that:
It is easy to see, from the outsider’s perspective, how a long friendship and a common heritage, culture, and ideals can bring all these people together, but hard to see how their theologies can co-existent deeply enough for them to form a movement of the sort they all seem to assume they have.
The article, and especially the comments thereafter, are also relevant to Catholic ecclesiology.
In a related article, Joe Carter remarks:
Since we’re discussing evangelicalism, it might be useful to answer the question, “What does it mean to be evangelical?”
While the term has a limited range of application, referring to specific traits, churches, convictions, and practices within Christianity, its denotation is so plastic that it makes it is almost impossible to succinctly define. Instead of shoehorning the word into an overly narrow definition, I’ll try to outline the central themes and relationships that help convey the connotations and senses in which the term is often used: . . .
Personally, I find the similarity of the issues regarding defining Evangelicalism or Anglicanism to also relate to current discussions within the Catholic Church regarding, say, Vatican II and the hermeneutic of continuity. Simply writing off issues of defining Evangelicalism as Protestant confusion regarding revealed truth about the Church is, I think, naive.