“It is important to understand that this was a political solution to an internal conflict that threatened the survival of the nation. The Articles of Religion (“Thirty-Nine Articles”) were a document which established legally what constituted “non-conformity” for the purposes of prosecution in the secular courts, that is, the legal boundaries of conformity to the Use of the Book of Common Prayer (what an individual did and said publicly, not what one believed). The Thirty-Nine Articles, however, are a specifically English legal document, not a theological statement of world-wide Anglicanism.”
Taken from “What is the place of the Thirty-Nine Articles in Anglicanism now?“, published by Akenside Press and free available along with other essays at our sister page, Anglican Catholic FAQ.