The other morning I tumbled down a theological rabbit hole and at the bottom, I discovered Fisher’s Catechism.
“Fisher’s Catechism” was originally called “The Synod’s Catechism” and was written by Scottish pastors Ebenezer Erskine and his son-in-law, James Fisher. It is a catechism of the Westminster Shorter Catechism, written in a question-and-answer format and laced with Scripture.
It led my heart to worship this morning! — as the study of theology should do.
For example, see this exposition on the Trinity. The first part is from the WSC.
QUESTION 6. How many persons are there in the Godhead?
ANSWER: There are three persons in the Godhead, the Father, the Son, and the Holy Ghost; and these three are one God, the same in substance, equal in power and glory.
Q. 1. Whence is it, that this article of our holy religion has been so much opposed by adversaries, in every period of the church?
A. The devil and his instruments have warmly opposed it because they know it is the primary object of our faith and worship; it not being enough for us to know what God is, as to his essential attributes, without knowing who he is, as to his personality, according as he has revealed himself in his word, to be Father, Son, and Holy Ghost, 1 John 2:23, — “Whosoever denieth the Son, the same hath not the Father.”
Q. 2. Is this doctrine of the Trinity, then; a fundamental article, upon the belief of which our salvation depends?
A. Beyond all doubt it is: because without the knowledge and belief of the Trinity of persons, we would remain ignorant of the love of the Father, the merit of the Son, and the sanctifying influences of the Holy Ghost, in the purchase and application of redemption; without which there could be no salvation, John 17:3, — “This is life eternal, that they might know thee the only true God, and Jesus Christ whom thou hast sent.”
The Center for Reformed Theology and Apologetics hosts the (free!) online version of Fisher’s Catechism. CRTA is a wealth of historic documents and has been serving the online Christian community for decades — I remember accessing it in the late 90s.