In my city children are taught in (mainly) two different ways: they are taught really strictly or not taught at all. Ive seen some people who grow up very conservative but when they hit their late teens they just stop with eveything and others who werent even taught to begin with just do whatever they want. There is people who just smoke and do drugs for fun and think it is cool, I have seen others drink, lots and lots of people have girlfriens and commit Zina, others just dont pray etc etc. This is somewhat interrelated to one of my previous questions Problem with marriage in the West.
I know it may be wrong to just say that this is all due to how some people have been raised but I feel like the way you are taught would play a significant role in this. What was the prophets approach to teaching others? Was he forceful or extreme and constantly saying you would be punished for one thing or another or extremly kind and leaves it up to the person he teaches what to do? What was his approach to teaching others to live at least a fairly Islamic life?