I sincerely wish that we had retained the custom, which I have stated was practiced among the ancient Christians.... a catechistical exercise, in which children or youth used to deliver an account of their faith in the presence of the church... a boy of ten years of age might present himself to make a confession of his faith; he might be questioned on all the articles, and might give suitable answers, if he were ignorant of any, or did not fully understand them, he would be taught. Thus the church would witness his profession of the only true and pure faith, in which all the community of believers unanimously worship the one God. If this discipline were observed in the present day, it would certainly sharpen the inactivity of some parents, who carelessly neglect the instruction of their children as a thing in which they have no concern, but which, in that case, they could not omit without public disgrace.

Cited from John Calvin Pilgrim and Pastor by W. Robert Godfrey pp. 106-7