Back in the first century CE, strong injunctions against pre-marital sex made a lot of sense:
- there were no accurate methods of diagnosing STDs
- there were no useful treatments for STDs
- there were no cures for STDs.
So, Paul wrote and the early Christian Churches taught that pre-marital sex is a serious sin, and that one must remain celibate until marriage.
But times change. At the present there are reliable methods of preventing the transmission of STDs, as well as detecting, treating and either curing or controlling STDs. A good case can be made that it is time to retire the old prohibitions against pre-marital sex as long as the sexual activity is practiced safely.
Apparently most people agree that pre-marital sex is OK. On the order of 93% of Americans currently are non-virgins when they marry.