Cue laments from certain Christians about the epidemic of singleness and adultescence.
Cue laments about class warfare, too, and the hegemony of upper middle class privilege as the measure of whether or not people are really committed to each other.
One of the things that has struck me over the last twenty years of reading the Bible is how there is no mention of fornication in the OT and how in the NT fornication is a sin which emerges fully formed. It also has struck me how adultery is condemned but polygamy is not. I have been completely unconvinced by evangelical attempts to argue that passages referring to second wives in Deuteronomy are somehow cases of prohibiting taking up a second spouse while the first spouse is alive. That the rabbis were able to reason that polygamy was less ideal than monogamous marriage is not especially hard to establish. But a bit of digging reveals that rabbis also interpreted that if a woman was an unwed virgin that it was not technically possible for a married man to commit adultery with her based on what the Torah's prohibitions entailed.
If evangelicals aged 18-29 are fornicating at a rate of 80 percent then now might be a good time for evangelicals to pay some attention to explaining how fornication gets no mention in the OT and yet gets mentioned in NT translations. I have a feeling that examining rabbnic discussions of case law or something like that might be a useful point of reference. Jesus said that divorce was permitted because of the hardness of mens' hearts. We might discover, perhaps, that the emergence of fornication as a moral and legal problem may have emerged from the hardness of mens' hearts, too. I'm not betting against it anyway.
Just in case someone wants to misunderstand this, I'm not arguing for fornication. I'm suggesting evangelicals bother to make a historical and legal case for how fornication ends up in the NT when it's not an issue in the OT. Some of the rabbis made a case that if a married man took an unwed virgin girl as an extra bride it was not legally speaking possible for him to be committing adultery. Evangelical attempts to claim the Torah forbade polygamy have been, so far, wildly unpersuasive. That a case could be made for monogamous marriage as the ideal is easy enough to do but that doesn't account for the realities of the case law in the Torah itself. It's impossible to get through Deuteronomy and avoid the mention that the offspring of favored wives are not to supplant the rules of primogeniture.
Now, particularly, if the moral law was not cancelled out by Jesus' death and resurrection then this makes it even more important to establish how and why premarital sex came under discussion as a moral and legal issue in the intertestamental period. Just some things to consider.