As I grew up both physically and spiritually, most of the life style I adopted were modeled around what I was taught in church. Sometimes it is the fearful reward that is acclaimed associated with bad behaviors that makes me act right. Another time it is the fear of the people that i know in church. More than the sermons, the Sunday school class tends to be more intimate in my opinion, especially with a manageable class. I have heard statements like ' your service is not complete without Sunday school'.
Common with most sermons is the fluid and exact references to some biblical verses which will enhance familiarity with the bible. When the sermons are expository, you get a special feeling of 'I know the bible more than anyone else'. The pastor is always giving the information. If correct very good! But any wrong info giving is often time not challengeable. Your life is always modeled around an icon which is the preacher. You risk adopting another mans life style for yours, common in today's Pentecostalism. Some men of God have even said " follow what I say and not what I do".
The practicality of the subject of discourse is another issue: The preachers just continue to pour down instructions that even themselves are incapable of following and expect the listeners to live by them. Following the common saying that it is easier said than done. Not to mention that sermons allows for in depth research by the preacher. Followed by a concise delivery in most cases.

On the contrary, Sunday school classes brings to you the reality of most subjects. Your experience, testimonies and challenges. You are able to relate with the general class expediently. Those who are yet to experience it get themselves on a fast track lane when it happens. Those who are yet to receive the miracle get reinforced assurance of receiving. One gets the other view of the same subject from another end. There is also the opportunity of asking questions for clarification and u are sure of getting diverse answers that meet your needs.
Because of the way the Sunday school classes are structured, lessons learnt stick better and they receive much practice attention from the listeners.
I also want to believe that spiritual life quality of Christian that passed through the Sunday school class system is envious. Teachers do not see themselves as God. They relate with you on your inability to get along with Christian tenets and lifestyle not how to win a battle with the devil (we are more than conquerors).
I use to remember then that malice was the in thing among children. Only the Sunday school classes were strong enough to soften our mind and as well forgive our friends of any wrong doing.
As a kid, memory verses helps to develop our retentive capacity of biblical quotations. Today, it has vanished with time. What you have left is kids discussing celebrities videos right inside the church after service (eminado and co).
Some denomination don't believe in the Sunday school system. Some have replaced it with the youth church. Our children no longer hold a place in the race for Gods kingdom. In a world where ungodliness spreads like virus, Christian children are becoming endangered.
Even in churches that prioritize Sunday school system, I am afraid to say they are losing focus. The essence of the Sunday school class is to build an indestructible Christian quality but now it is just a way to buying time and to complete the worship day.

I hold on to the fact that the Sunday school class system is better than the sermons we hear every Sunday. It should be brought back and adopted.
The Christian faith needs soul revival not miracle revival all around the world and this can be best achieved when there is a discipler and followers. This is just my opinion for a special Sunday like this.
Feel free to antagonize me and I will welcome all forms corrections and contributions

@OP, I am in full agreement with you and wish i could like your post a million times.

I believe the church needs more bible teachers now than ever before and I price a bible study over and above any miracle crusade or 'powerful preaching'. The total absence of a question and answer session in Sunday and weekly services has increased biblical illiteracy among young Christians and this makes them eternally yoked to the whims and caprices of their pastors. Engage them in a discussion and you start hearing "my pastor said,..." or "papa said,...".

If pastors wish to be honest and aren't looking to create zombies who must obey their every instruction (whether good or bad), they should encourage and give more time to bible study, Sunday school etc where members can ask questions and get clarification. Even the pastor doesn't know everything and could learn a thing or two from his members.

If your pastor is on the wrong track or led astray and you can't ask him questions, then you're done for.

Candour: @OP, I am in full agreement with you and wish i could like your post a million times.

I believe the church needs more bible teachers now than ever before and I price a bible study over and above any miracle crusade or 'powerful preaching'. The total absence of a question and answer session in Sunday and weekly services has increased biblical illiteracy among young Christians and this makes them eternally yoked to the whims and caprices of their pastors. Engage them in a discussion and you start hearing "my pastor said,..." or "papa said,...".

If pastors wish to be honest and aren't looking to create zombies who must obey their every instruction (whether good or bad), they should encourage and give more time to bible study, Sunday school etc where members can ask questions and get clarification. Even the pastor doesn't know everything and could learn a thing or two from his members.

If your pastor is on the wrong track or led astray and you can't ask him questions, then you're done for.

Thanks for shining more light on the topic. I like your perspective. I chose not to attack the men of God too big. But you have done it the right way. This is what we should learn on Sundays. I beseech the appropriate authority to move this topic where it belongs so Christian can teach and then be thought.