Why do we do Church School? Why did I do Church School?
I think there are different objectives amongst Church leaders (priests and other leaders), other long-time parishioners, the parents and the children.
Church leaders and long-time parishioners want all those new souls to be taught something important. But sometimes lay people seem to equate teaching religion to teaching physics or biology: make the kids learn a few prayers by heart, a few good Biblical quotes (especially in more evangelical circles)... and make sure there is no noise during the grown-up service. Not exactly my idea of Church school!
My idea on prayer is that one needs to understand why and how one should pray. Likewise, in understanding the Gospel, one comes to learn how we went from the 10 Commandments given to Moses to the two "great" commandments given by Jesus. That it is not "toning it down" or making it easier, but rather going beyond the letter of the law to principles that we need to put in practice.
One additional benefit of Church School is understanding the particular wording we use, the conditions in which the Gospel was delivered, etc. Our sermons are not always appropriate for children, and Church school may also help by giving examples that are more appropriate to their experience.
But this brings other questions. Our parish doesn't have any kids right now, but we have a decent-sized group of young adults who are either new to Christianity or who might have been in Church as children but out of the Church for 10-20 years. Some were born in Québec, but others come from different countries – with different mother tongues, cultural experiences, etc.
Do we all understand the readings and prayers? Most people pretend to do so, or at least they are so used to hear them and say them that we don't pay attention. And what about sermons where the predicator uses British poetry to illustrate her teaching?
In a way, I see common points between teaching to children and to newcomers. And some of these teachings might probably apply to regular church goers as well.