There is only one completely surefire method of avoiding diseases transmitted through sexual relations: abstinence. NO form of "protection" is 100% safe. Taking into account the serious ramifications of sexually transmitted diseases when there is a KNOWN way to completely avoid them, it is beyond logic that some continue to promote "protection" which is not completely safe. The negative reaction towards abstinence teaching is quite shocking.
Reducing Humans to Animals
Human beings have the ability to show restraint in the area of sexual relations. To claim that it is not possible is to reduce human beings to mere animals. (Of course, wholesale slaughtering of the most vulnerable and innocent human beings has already begun to reduce us to animals.) Despite society's overwhelming encouragement of improper sexual relations, human beings have the capacity to show restraint.
Excuses
The main excuse to argue against encouraging abstinence seems to be "But they're going to do it anyway." Sexual relations between anyone other than a validly married heterosexual couple is wrong. Period. (If you feel this is just "an opinion," see the Moral Relativism section.) A number of immoral (including illegal under local/state/federal law) things are "going to happen." Banks will be robbed. Should we have classes teaching would-be bank robbers how to rob a bank without anyone getting hurt? Students are going to cheat on homework or exams. Perhaps this might be done in a class taught by a teacher with high blood pressure problems. Should we instruct students on how to cheat without getting caught in order to avoid stressing out the teacher? Does this sound ludicrous? It is. We do not give out instructions on how to accomplish immoral practices in the "safest" manner. Why is there any exception with sexual behavior?
It is obvious that society pressures young people into immoral sexual relations. What is baffling is that those who are so concerned about promoting "protection" seem to miss the root of the problem. These are intelligent people. How can they overlook the obvious answer to the prevention of unsafe sexual relations: CHANGE THE CULTURE. Work to get society to stop encouraging immoral sexual relations. Most elements in society will resist such change since there is quick and easy money to be made in encouraging immoral sexual practices. When that happens, remind young people directly that they HAVE the capacity for restraint. Why lower the standards to encouraging use of "protection" that is NOT foolproof? Why give young people a FALSE sense of security? Why not go for higher standards? Don't our young people deserve that much? Shouldn't young people be told that they have the ability to control their temptations despite the assault by society? Or is it preferable to LIMIT young people and essentially tell them they are not strong enough to exercise control and restraint? Afterall, if the goal is to prevent the spread of STDs and reduce teen pregnancy, abstinence fits the bill perfectly.