I disagree off course - regardless even of not believing in a god.
"the perceived authority commands it", is not a reason. That just obedience to a perceived authority. The answer to WHY does the authority command it, would be the actual reason.
Since you presume no God exists, that would make sense to you. In Christianity, you have it backwards. God commanding anything is good enough reason to do what he commands you to do or avoiding what he commands that you not do. The other earthly benefits are just bonuses.
The alternative to "abstinence" is not "having unprotected sex with everyone you meet on the first date".
Not true, abstinence is until marriage. And many of these consequences are consequences of sex between the second date and before marriage.
If in this day and age, you still get pregnant while not wanting/planning to, then some sex education might be in order.
Abortions due to unwanted pregnancies happened quite a bit before Bush's abstinence-only sex education was established. These happened in spite of sex education that covered all manner of birth control.
I'm not married. I have a kid. I can guarantee you that he has a MUCH more stable home then plenty of other kids I know of whom the parents ARE married.
And same as above: in this day and age, you have more then enough tools to avoid getting pregnant.
Our child was 100% planned. We've been together for 15 years before we decided to have a child. And needless to say, we had plenty of sex during those 15 years.
If what you say is true, you're not in the majority. And in Christianity, a non-married cohabitation that is more stable than a bad marriage is not a justification for not marrying and putting in the work for a good marriage.
Again: the alternative to "abstinence" is not "sleep with everyone you meet on the first date".
Again: Not only is abstinence more than not sleeping with everyone you meet on the first date, but many of the issues I cited start with sex that happens at some point after the second date and before marriage.
I know plenty of people with those problems. ALL of them got kids while married and then divorced. Every single last one of them.
Plenty of cohabitators and non-cohabitators also have those problems. When people don't fornicate and cohabitate, there are less of them. And since all of the people you know who have these problems got married and then divorced and then had these problems (if I'm understanding your post correctly) then you haven't had the experience I've had of hanging out with people who panicked for a second when women they didn't recognize were greeting me. Why? Because these guys would get blackout drunk.
Those are the types of problems you end up with, if you sleep with anyone you meet on the first date. Once more: the alternative to "abstinence" is not "have sex with anybody before really getting to know eachother".
If you get to know eachother well first, you won't have such problems.
Again, abstinence is more than that, and these problems are not limited to sleeping with people on the first date.
That is utterly false as every sexuologist will tell you.
In fact, the opposite is true. On both counts.
Wrong.
Does Sexual History Affect Marital Happiness?
Next to that, you're also wrong. Intimacy acts like a glue. Sex is just one form of intimacy and it's not even the most important one. There's far stronger glue. And that is honesty and open communication. To share and talk about your interests, your ambitions, your hopes and dreams, your childhood experiences, etc. To dig into eachothers minds and memories. That connects people a lot more then sharing an [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse].
Sex surely is an imporant aspect, but in my experience, it is by far not the most powerfull "glue" in that sense. Talking and opening up "your soul" is.
There are other forms of intimacy, sure. And they can cloud judgement at the wrong time. But do you seriously mean to suggest that talking about those things can cause people to look past gross irresponsibility and abusive behavior more than sex can?
To give you an idea: I was in a deep and meaningfull relationship with my current partner for almost 2 years (2,5 - 3 if you also count the period of flirting / casual dating) before we shared a bed together. By that time, I dare say that we already had a much deeper connection then a lot of "abstinance" people by the time they get married in a hurry.
And I don't advocate marrying sooner than that, for the record. There are "abstinence people" that abstain for that long, and get married, and have children, and stay married. I'm friends with them. My parents didn't take quite that long to get married IIRC, but they're still together, and they have said that waiting helped their relationship.