Good question. I don't think that sex continence before marriage is something bad. It's choice and decision of every person - Make or Not to Make Love until being married. Moreover, nowadays many teens are involved in sexual interactions VERY early, before they realize whether they need having sex or not.
But what comforts is that there are also many teens who decide not to make love unless marriage knots are tied. I think that we have freedom of choice.
Sure there are still countries where having sex before getting married is a kinda sin, but gradually the mankind is getting rid of this tradition. Personally I believe that IF partners DO love each other, have have SERIOUS realtionships,and are sure they're going to marry, they may make love.