While many Christians are actively involved in devotional Bible study, he laments the lack of formal catechetical study, without which, he says, “Well-intentioned minds and hearts will repeatedly go off track.”
Like Scripture says, we all, like sheep, have gone astray. We need constant shepherding and guidance, and knowing and repeating a catechism can be a way to ground our hearts in unchanging truth. The tradition of repeating established statements of faith helps with that shepherding, and it has a long history. Many modern congregations, however, have allowed a lapse in the practice.
In Taking God Seriously: Vital Things We Need to Know (Crossway, 2013) Packer says:
As the years go by, I am increasingly burdened by the sense that the more conservative church people in the West, Protestant and Roman Catholic alike, are, if not starving, at least grievously undernourished for lack of a particular pastoral ministry that was a staple item in the church life of the first Christian centuries and also of the Reformation and Counter-Reformation era in Western Europe, but has largely fallen out of use in recent days.
That ministry is called catechesis. It consists of intentional, orderly instruction in the truths that Christians are called to live by, linked with equally intentional and orderly instruction on how they are to do this.