I do not know the origins of the phrase “generous orthodoxy” but it seems to fit the Church of England as it was designed rather well. The Roman Catholic Church was not broad enough in the sixteenth century to include those who held Reformed views. But among Reformed Catholics there was also disagreement which by and large could not be lived with (“good disagreement”) so that Lutherans ended up forming one denomination, while those who followed Calvin and Zwingli formed separate churches. Perhaps only in England did the Reformed Catholic consensus hold so that both those holding Lutheran views and those looking to Geneva (or Scotland) were held together in the one established church. Roman Catholics were of course excluded, as were Baptists, and in the end even Presbyterians (the Great Ejection). So there were clear limits not only to orthodoxy but perhaps also to generosity. The Thirty-Nine Articles circumscribed the parameters, while the Homilies filled it with more content and clearer definition.
The Tractarian movement pushed the boundaries, declaring the Church of England a via media not between Wittenberg and Geneva but between Rome and the Reformation. The English Church moved from seeking and finding doctrinal agreement among the disagreements on details to accommodating strikingly different readings of the same words. But it is arguably liberal revisionism since the 20th century that is killing off generous orthodoxy, making people forget that “generous orthodoxy” requires both generosity and orthodoxy, tolerance and discipline.
The proposed Prayers of Love and Faith were presumably meant and agreed upon as an expression of “generous orthodoxy.” The Christian doctrine of marriage and the Christian ethics around sexual intimacy were left intact, or so it is alleged, and a new freedom was found within this consensus which would allow some to celebrate the good and healthy aspects of same-sex relationships with couples who form a household, and others to refrain from endorsing patterns of relationships that might invite sexual temptation.
Alas, even before the proposals were presented to the public it became clear that this “generous orthodox” line could not hold. A number of bishops argued that the doctrine should in fact change and the claim made by campaigners that the doctrine of the Church of England discriminates against LGBTI+ people remained largely unaddressed.
An analogy may help to explain what might have happened: Imagine the Bishops, in view of concerns about the gendered language of the traditional formula, had allowed for “In the name of the Father, and of the Son, and of the Holy Spirit” to be regularly replaced by “In the name of the Creator, the Redeemer, and the Sustainer.” Imagine that some Bishops were very uncomfortable with this because the triune God is then no longer spoken of as who He is in Himself from before the creation of the world (the gendered “He” seems unavoidable, even if God is of course not male) but defined in relation to us. But, being generous, they allowed for this provision on the understanding that it does not as such mark a departure from orthodoxy.
Now imagine further that there are people complaining about the discrimination against Unitarians and Jehovah’s Witness and others in the selection process for ordination in the Church of England and there being no official explanation forthcoming why such “discrimination” is in the nature of the thing. Add to this Bishops who argue that the insights of modern philosophy lead us away from a Trinitarian understanding of God. Even without them also adding that “In the name of the Creator, the Redeemer, and the Sustainer” could be used by those who believe that God is one person who has revealed himself in three modes, it is clear that this is not about being more generous within the existing orthodoxy but about re-defining what constitutes orthodoxy, given that we all take the Scriptures seriously. Whatever the Bishops think, for those who hold to the received understanding of orthodoxy and have seen no reason to change this, Unitarians and Jehovah’s Witnesses are without question outside the bounds, even if it may be granted that subjectively they hold a high view of Scripture and “merely” read it differently and even if one affirms gladly that they have all the civil rights of other people.
The question whether we can be more generous within our received orthodoxy is one and it relates to attitudes and behaviour and pastoral practice; the question whether in order to be truly “generous” we need to redefine what constitutes orthodoxy is another. Let us distinguish between the two.