I should know. I am one. We teens are conceited, rude and noisy, and as a rule, we think we know far more than we do. The sane, adult world wisely stays as far away from us as possible, shutting us up in school and trying to ignore us until we start becoming civilized. The Christian world often does the same.
Teenagers can be pretty scary and difficult to witness to.
You don't understand us, our world, or our motivations. You don't know how to talk to us, whether to address us as children or as adults. We start laughing when you are trying to be most serious, and you know we will start joking at your expense the moment you turn your back. Thus a gold mine goes to waste. The quiet, sensible Christian, however, views this energy with fear and mistrust.