The other exiled brethren, on receiving this invitation, had enough of the wisdom of the serpent to ask, "Are we to be allowed to use our own prayer book ?" The answer of the godly of Frankfort evaded the question.

At last the Frankfort Puritans showed their hand: they disapproved of various things in the Prayer Book.

Knox, summoned from Geneva, a reluctant visitor, was already one of their preachers.

In November 1554 came Grindal, later Archbishop of Canterbury, from Zurich, ready to omit some ceremonies, so that he and his faction might have "the substance" of the Prayer Book.

Negotiations went on, and it was proposed by the Puritans to use the Geneva service.
But Knox declined to do that, without the knowledge of the non-Puritan exiles at Zurich and elsewhere, or to use the English book, and offered his resignation.