Increase 'Equipper' Lewis Varley on Theological Education by Extension and catechesis
In their 2010 book Grounded in the Gospel: Building Believers the Old-Fashioned Way  authors J.I. Packer and Gary A. Parrett tell us that between the second and fifth centuries of the early church, the church’s ministry of grounding new believers was known as catechesis.
Those who became Christians often moved into the faith from radically different backgrounds and worldviews. The churches rightly took such conversions very seriously and sought to ensure that these life-revolutions were processed carefully, prayerfully, and intentionally, with thorough understanding at each stage. 
Following this period, the authors explain how, for various reasons, the practice of catechesis was lost to the church. However, during the Reformation:
[T]he rigorous work of nurturing believers and converts in the faith once delivered to the saints, a didactic discipline largely lost for most of the previous millennium, had become normative again for both Catholics and Protestants. 
But then, moving into the modern period,
[T]he church in the West has largely abandoned serious catechesis as a normative practice. 
In a fascinating insight, Packer and Parrett suggest that one of the causes of this decline was the success of the ‘Sunday school movement’ in North America, which ‘substituted an instilling of familiarity with Bible stories for any form of grounding in the basic beliefs, practices, and ethics of the faith.’ 
The authors then give a definition of catechesis:
Catechesis is the church’s ministry of grounding and growing God’s people in the Gospel and its implications for doctrine, devotion, duty, and delight. 
This broad and deep definition provides at least four strong resonances with the approach and goal of TEE. Like TEE, this definition of catechesis is:
has the purpose of growing all God’s people
holistic, attending to head, heart and hands
The rest of Packer and Parrett’s book could well be read as a theological and Biblical apologetic for TEE as one form of catechesis. The book would be beneficial for anyone engaged in TEE as part of their ministry in the church. Given the wisdom and experience of the authors, it would prove highly fruitful to read the book as a lens through which a typical TEE curriculum could be assessed and reviewed for content and effectiveness. In particular chapter 10, Championing Catechesis in Contemporary Congregations, includes twenty questions relating to catechesis, but all of which could equally usefully be asked of a TEE programme . These include:
What do we as a church community consider to be essential content [in a catechism]?
How are we engaging the heads, hearts and hands of our congregants?
What are the -isms of the culture that must be countered with the truth? How can we do so?
What idols of the culture must be countered with the Life?
Do we have a clear vision for progress in our catechetical journey?
Questions such as these are also the ones which TEE course writers must grapple with as they work to produce new and contextually significant courses for local and wider contexts.
When people hear the word ‘catechism’ their minds may well jump to a question-and-answer format of Biblical instruction. While that would be somewhat similar to elements of TEE (systematic memorisation plays a part in many TEE courses, and answers to questions in TEE lessons are often short or multiple-choice, which lend themselves to an oral approach), Packer and Parrett are clear that they do not limit catechesis to this more traditional question and answer format. As they say:
There is more than one way to skin a cat, and no limit should be set to human ingenuity in packaging the catechetical process - provided only that the syllabus of the Gospel doctrine gets fully and properly covered, and that the need for the fourfold response to it we described above remains in view. 
By this ‘fourfold response’ they mean: answering questions on what has been presented; working out implications and applications; positioning oneself to act on these implications now seen; and actually obeying by forming the appropriate habits of thought and behaviour. Once again, the underlying andragogy of TEE would strongly resonate with all four areas.
Packer and Parrett set out five different ‘frames’ for catechesis . These are catechesis of:
In each case, it is possible to align TEE courses with one (or more) of these frames. For example, Abundant Life would fit with the faith frame; The Big Picture with the Scripture frame; and The Life of Christ with the Gospel frame. A reflection on these five frames might also suggest areas where new TEE courses are needed to supplement those that are already being widely used.
Packer and Parrett’s urgent call for the church to return to catechesis, broadly understood, finds a strong affirmation in the ministry of TEE worldwide. At the same time, the authors indicate how many churches and denominations are heeding this call: their appendix, Resources for Further Study, includes a list of ‘Contemporary Catechetical Efforts and Related Proposals’ , which includes Alpha, The Baxter Model, and Christianity Explored. Another more recent curriculum which would also fit here is The New City Catechism, which came out of Redeemer Presbyterian Church in 2017.
In summary, there is plenty of room for exciting reflection and cross-pollination of ideas and approaches as TEE is set within this growing family of catechism-based resources to help grow God’s people worldwide through church-based training.
 Packer, J.I. and Gary A. Parrett, Grounded in the Gospel (Grand Rapids, MI: Baker, 2010)  ibid. p22  ibid. p23  ibid. p24  ibid.  ibid. p29  ibid. p181ff  ibid. pp190-191  ibid. p80ff  ibid. p217