The Catechism of the Catholic Church teaches that the primary educators of the children are the parents. When the parents are not only providing material needs, but teaching and forming their children by words and deeds, the proper education of their children is better safeguarded. However, when parents are not good examples of faith, but merely sending their kids to Catholic schools and programs, the children soon realize that they do not need to practise what they learn either, since their parents do not. This same mentality is found regardless of the quality of these Catholic programs or classes. They certainly could help a bit, but the big question is their parents’ own faith practices.
It is for this reason, that in the Rite of Baptism for Children, it stipulates that the role of godparents primarily is NOT for the education of the children or to replace their parents, as has been popularly believed. Rather, their foremost duty is to assist the parents to fulfill their Christian duties, that is, among other things, to be the first and the best of teachers of the faith for their children.
When the parents are failing to live out their faith, it is the duty of the godparents to be on their case. A softer way to put it is to find out what is blocking them from God, if there are programs or means by which their faith may be re-ignited, like retreats or pilgrimages or a book or video, etc. And above all, lots and lots of prayer and fasting. Their lukewarmness is not only jeopardizing their own eternal salvation, but that of their children as well.
Of course, similar means may be employed for the children who are losing their faith. But if they have never experienced someone close comes alive in his faith, be it someone in the family or among close friends, it would be very difficult. So I often tell people: pray that someone they can trust would come to believe, or that a strong Christian that they could trust may enter into their lives. Faith is most powerfully transmitted when encountered personally.