The 20th century saw dramatic changes in attitudes toward what is considered to be proper sexual behaviour, aided by easy availability of birth-control pills.
We live in a promiscuous society where confusion and misinformation about sex is rife and biblical instruction on the subject is ignored and ridiculed.
Sadly, the percentage of professing Christians who engage in extramarital affairs and end their marriages in divorce is just as high, and sometimes even higher, than among non-Christians.