A catechism is nothing more than a statement of belief. If you say, "I believe that Jesus Christ is the Son of God.", that is a catechism and you can cite scripture to support your catechism. Catechisms organizes our doctrine.
Here is the Heidelberg Catechsim.
Thanks Harley.
Isn’t the theory since Luther that scripture is readable and its interpretation obvious? Why would you need to pick one interpretation organize that into a statement of belief?
I think you may be saying it’s just a different wording or organization; but isn’t it also to say what you believe versus what others believe - based on the same scripture, alone?