The scripture is written as a scroll, wrapped in burning flames untouchable by those who are not disciples of the Gropaga faith.
Each page features three distinct paragraphs of text decreeing stories of various canonical aspects of the faith. These range from formal declarations of enemies and places to important artifacts. Interestingly, the scripture also seems to house some news regarding the congregations themselves, somewhat like a religious tabloid. On the first page, for example, it can be read that several of those in one of the congregations were tried for their piety, and only one survived the trial.
All imagery in A Compiled History of the Gropaga Faith is culled from original source material created by devotees to Inglip, the deity of the Gropagas. It is altered to fit the style of the scripture, which includes cutting out the important aspects of the story of each paragraph, thus condensing the paragraph into an easily readable visual form, subtle as it may be.
A Compiled History of the Gropaga Faith is entirely canonical; it is seen on the sidebar of the /r/inglip subreddit. Most, if not all, of the information in the scripture is canonical and chosen for publication by gauging the net "karma" of the submission. Karma is an invisible, subjective approval system originally thought up by Inglip himself and bestowed graciously upon Reddit as a whole. The concept of karma is thought to date back to Inglip's time as ruler of Diagral.
Regardless of these contentious subjects, however, A Compiled History of the Gropaga Faith is, alongside this very Wikia page you gaze at, the most canonical source of news and materials regarding the Gropaga faith.
...praise be to Inglip.