Actually, over 50% of kids DO NOT HAVE SEX before the end of high school. Thus, clearly, a great many teenagers are able to control themselves - even in a culture that glorifies any and all sexual acts. For those teenagers that do have sex, and even when they use a condom (which is useless with regard to many viral STDs), they risk getting: herpes, AIDs, and human papillomavirus. Further, condoms break frequently (10-15% of the time), leading to unwanted pregnancies and bacterial STDs, many of which no longer respond to antibiotics. A kid who's been taught that wearing a condom constitutes safe sex thus only needs to have sex about 7 times, on average, before he discovers that he's been lied to. By then, it's often too late. JediGirl - I don't know if you're a mom, or if you'll be one some day. When you are, go ahead and tell your kids that you expect that they will have sex, and that they should wear condoms. When your son or daughter daughter gets herpes (untreatable), or when your daughter gets pregnant and the boy disappears and you start to think about abortion (killing your grandhild), maybe you'll see things in a different light.
That's why I stress the importance of being sure of who you're with. Not everybody has an STD. I think it best to be with your partner for some time before having sex.