Here is a brief article from the ELS (Evangelical Lutheran Synod – a small conservative Synod) on Luther’s Catechism and the Catechetical tradition in Lutheran churches:

Why and How Did Martin Luther Write His Catechisms?

What does this mean?

For catechized Lutherans, this is a very familiar question. It is a simple question; a question that seeks a simple, clear, and brief explanation. It is the natural question of a curious mind. And that is exactly why Dr. Martin Luther used it throughout his Small Catechism. His goal was to develop resources for parents, teachers, and pastors to use as they taught the young and uneducated the fundamental teachings of the evangelical Christian faith. But don’t let the question’s simplicity fool you into thinking that the Small Catechism is a simple book. It was not the light afternoon’s work of a Wittenberg theologian.

Why did Luther write the Catechisms?
Luther realized that there was a need for a new evangelical catechism. In fact, he had asked a couple of colleagues to write one, but they never finished it to his satisfaction. It wasn’t until he visited a number of congregations in Saxony that he was “constrained” to take up this task himself.
In his Preface to the Small Catechism (p. 9) Luther wrote, “The deplorable conditions which I recently encountered when I was a visitor constrained me to prepare this brief and simple catechism or statement of Christian teaching.” What were these “deplorable conditions?” “The common people… have no knowledge whatever of Christian teaching, and unfortunately many pastors are quite incompetent and unfitted for teaching.” Luther couldn’t stand by anymore and let a truly Christian and evangelical catechism go unproduced.

How did Luther write the Catechisms?
As a parish pastor, Luther preached to and instructed the youth of the congregation. During his tenure, he had preached a few series of sermons on the Commandments, the Creed, and the Lord’s Prayer that served as the foundation for the Large Catechism. In fact, in the Short Preface to the Large Catechism, Luther actually calls the Large Catechism a sermon.

The Large Catechism was the first to be published, in April of 1529. It was written for the basic and foundational instruction of the instructors, namely parents, teachers, and pastors. Remember how “many pastors [were] quite incompetent and unfitted for teaching?” Now they, as well as parents and teachers, would at least have a resource for preparing themselves to teach and expand upon what the children would memorize from the Small Catechism.

The Small Catechism was published a month later, in May of 1529. And it is this Catechism from which the famous “What does this mean?” comes. Luther suggested that parents, teachers, and pastors constantly (as in weekly, even daily) review these texts and explanations verbatim so that the students learn them by heart. In fact, the first words of the Catechism are “As the Head of the Family Should Teach Them in a Simple Way to His Household.”

Are Luther’s Catechisms still useful today?
Today, as in Luther’s day, there is still a need for faithful resources to teach the foundations of the evangelical Christian faith. Since 1529, Lutherans have been learning and memorizing Luther’s Small Catechism. Its truths are timeless, because they are eternal, divine truths. They are worth constant study and committing to memory even for the learned, because they will never change. They bring the young to maturity and develop the unlearned into grounded Christians. They are also a ready-made “defense to everyone who asks you a reason for the hope that is in you” (1 Peter 3:15). After all, aren’t they basically asking, “What does this mean?”

Reverend Samuel Gullixson
Our Savior Lutheran Church

Bishop, CA

Why and How Did Martin Luther Write His Catechisms? (els.org)