Youth celebrate Valentine's Day by taking a vow of abstinence. The Day of Purity is aimed at encouraging singles of every age to remain sexually pure — a strong counterpoint to the popular cultural message to have sex early, often and with many.Young people are bombarded with messages — through mass media, music and peer pressure — encouraging them to become sexually active at a young age and even to experiment with homosexuality.Take, for example, one ninth-grade health textbook that says "testing your ability to function sexually and give pleasure to another person may be less threatening in your early...