People hear the same things over and over until they are meaningless to them. I talked to a kid at school today who had heard about God, but never really cared, because he thought that If he led a Godly life, he'd be bored. This struck me as odd, but I understand now why people have begun to think this way. It's called: language. If you tell a teen now that Jesus died for them, and they can be saved if they believe this, they'd most likely tune you out. They've heard it before. But if you reach them at their level of language, and you get rid of their doubts then the person becomes open to what you have to say.