The doctrinal core of the Catholic Castle is "The Light of the World." This is a six-part illustrated life of Jesus Our Lord, accompanied by a text which explains the teaching of "The Catechism of the Catholic Church" in the light of that Life. "The Light of the World" was originally created and published in print by David Fielding towards the end of the 1990s. It is reproduced exactly, in its entirety, in Catholic Castle.
Not only did this work receive imprimaturs from the local bishop, but it was submitted to the "Ad Hoc Committee to Oversee the Use of the Catechism." (This committee operated under the aegis of the United States Conference of Catholic Bishops.) The Light of the World was granted a "Statement of Conformity with the Catechism." More than that, however, the author and publisher (David Fielding) was personally commended for his extraordinary degree of fidelity to the content of the Catechism.
The relevant documents are listed below. Click any one to see a pdf file of the original. (Note that "Brightstar Publishing" was the predecessor of "Castle of Grace.")