Heidelberg Catechism
[1]: 230 Its original title translates to Catechism, or Christian Instruction, according to the Usages of the Churches and Schools of the Electoral Palatinate.
He commissioned the composition of a new catechism for his realm, which would serve to both teach the young and settle the differences in doctrine between Lutherans and the Reformed.
[1]: 230–231 One of the aims of the catechism was to counteract the teachings of the Roman Catholic Church as well as those of Anabaptists and 'strict' Gnesio-Lutherans like Tilemann Heshusius (recently elevated to general superintendent of the university)[3] and Matthias Flacius, who were resisting Frederick's Reformed influences, particularly on the matter of the Eucharist.
The Catechism based each of its statements on Biblical source texts (although some may call them 'proof-texts' which can have a negative connotation), but the 'strict' Lutherans continued to attack it, the assault being still led by Heshusius and Flacius.
[2]: 18–19 A proponent of this tradition, Lyle D. Bierma, also argues for this by pointing out that the theme of 'comfort' (evident in the famous first Question), is also present in works of Luther and Melanchthon which were significant in the Reformation of the Palatinate.
[2]: 21 In its current form, the Heidelberg Catechism consists of 52 sections, called 'Lord's Days', to be taught on each Sunday of the year, and 129 Questions and Answers.
That I, with body and soul, both in life and in death, am not my own, but belong to my faithful Saviour Jesus Christ, who with His precious blood has fully satisfied for all my sins, and redeemed me from all the power of the devil; and so preserves me that without the will of my Father in heaven not a hair can fall from my head; yea, and that all things must work together for my salvation.
Wherefore by His Holy Spirit He also assures me of eternal life, and makes me heartily willing and ready henceforth to live unto Him.Bierma argues that the opening lines of this answer are remarkably similar to Luther's explanation of the second article of the Apostles' Creed in his Small Catechism (1529), 'that I may belong to him [...] [Jesus Christ] has set me free [...] He has purchased and freed me from all sins [...] from the tyranny of the devil [...] with his [...] precious blood'.
[2]: 22 The Catechism is most notoriously and explicitly anti-Roman Catholic in the additions made in its second and third editions to Lord's Day 30 concerning 'the popish mass', which is condemned as an 'accursed idolatry'.
[11] In some Reformed denominations Question and Answer 80, the first of Lord's Day 30, have been removed or bracketed but noted as part of the original Catechism.
