Indeed, Leibnitz's two great questions are the most important and would lead to the answer to the question which I proposed for teenagers.
It seems to me that teenagers spend a lot of time of reflecting on themselves, trying to "stand on their own two feet". But truly a purpose in existence cannot make sense without faith in God.
####But truly a purpose in existence cannot make sense without faith in God####
As someone who has much faith in God, I can still conceive of an individual who feels a purpose in existence without God. However, I doubt most people could, and worry deeply about the effects of secularism on our society. As a conservative I recognize that the other side understands this. The ACLU isn't involved in these battles (not just evolution, but the Boy Scouts, abortion, etc.) for nothing. They have societal ramifications.