Whether a man accepts the historicity of Jesus or not will not, so far as I can see, affect his behavior if he views the narrative in the Gospels as an expression of the best values we know, and the image of human nature at its best. Ray Billington, Response to the Committee of Doctrinal Appeal, June 1971
It would be easy to cry ‘heresy!’ but not so easy to answer the question [Billington] poses – ‘Who is the heretic – the man who says there is no God, or the believer who devalues his neighbour by his life-style, his churchmanship and his lack of feeling for other in their need? Review of The Christian Outsider, David Blatherwick, The Methodist Recorder, 1971
The Discipline of Canonical Enforcement
An essay by Rev Pierre Whalon, Bishop in Charge of the Convocation of American Churches in Europe.
Authority in the Anglican Communion
By Edward Norman; Ecclesiastical Law Society Lecture given during Lambeth Conference, 1998
Three chapters of Hilaire Belloc's (idiosyncratic) book on heresy: Introduction, Overview, and "Modernism"
An article from L'Osservatore Romano, identifying "religionless Christianity" or "atheistic Christianity" as the "the great heresy of the 20th century".
Sister Churches and Sisters in the Church
Anthony Freeman's essay, originally published in Modern Believing, does not directly address the question of doctrinal diversity; however it does illustrate ways in which ideas in modern psychology could be used to challenge the way we think about inclusion and exclusion.