Its intricacy lies in the character of the documents before us - religious formularies consisting partly of matter established in usage long before they were written down in their present shape, partly of additions made at the time of writing.
The progress of the archbishop's opinion towards that middle Protestantism, if it may be so called, which he did so much to impress on the formularies of the Church of England, was gradual, as a brief enumeration of the successive steps in that progress will show.
Cranmer was therefore enabled without let or hindrance to complete the preparation of the church formularies, on which he had been for some time engaged.
A catena of opinions may be produced in favour of almost any theory; but formularies express the collective or average belief of any given period, and changes in them are a sure indication that there has been a general change in ideas.
The main points in which the pre-medieval formularies of both the Eastern and the Western Churches agree in relation to the Christian sacrifice are the following.