Thank you for your prescience or at least sacrifice.

When I was a teen I used to sometimes play "what's the worst thing I can possible imagine" as a kind of mental exercise. I really, really wish I could undo the years of playing this game, now.

And the Lord sayeth, "creampie your sister-in-law or I'll fucking kill you."

Fun fact: In the Indigenous Australian society I'm most familiar with, if you're a man and your brother dies, his wife is now your wife, and you have his familial obligations. This is to ensure that his family will be cared for.

his brother’s widow

Tamar is an interesting character in her own right, and worthy of being named.

After this, she’s supposed to marry Judah’s (Onna’s dad’s) third son, but considering he just lost two, he doesn’t want it to go through. He sends her home to her parents and blows her off when she asks when the marriage is going to happen. (The Bible has a lot of verses about leaving parts of your field unharvested for widows. Not having a husband = hellish poverty.)

She eventually gets fed up with this, disguises herself as a temple prostitute, Judah shows up, has sex with her, and gives her a family emblem as an IOU.

Later, she ends up pregnant, so the village elders drag her before Judah for punishment (he’s her father-in-law still technically.) They are going to put her to death, and Judah asks her who knocked her up. She produces his family emblem, and he has to be “well, you got me, I guess I have to take care of you.

This seems to me a bit outside your usual family obligations

It was actually the law to do that, IIRC. https://en.wikipedia.org/wiki/Yibbum

What if they had a girl?

It is. I changed it now. Maybe you want to try again?

bah, go pick a fight somewhere else

naked guy

Neaniskos in the original Greek, not just a boy but a little boy

Oh my god! 😉 Poor me, making a witty non-serious comment and now having to defend myself in a theological discussion.
And this with a hangover from being punished by god for committing the sin of alcohol.

Anyway, here goes.

"mental disorder"
That isn't necessarily a bold statement.
mental disorders exist in a wide range.
From fear of public speaking to smearing yourself with feces or chopping your mother to pieces because a voice told you she is the devil.

Somewhere in that spectrum lies religion.
While I came to that conclusion myself, I have learned I am not alone.
Sometimes labeled as a form of delusion which is a psychiatric condition.

When a majority of humans suffers from this condition it is logical it becomes acceptable and the others will conform, regardless of how crazy their beliefs are.

catholic sins were only defined later

You are making an artificial distinction. Catholicism can be, but shouldn’t be viewed as a thing with a start. It’s part of a continuum. Judaism>Christianity>Islam. Catholic sins weren’t defined later. Like all culture, they evolved from earlier sins. Even calling them Abrahamic Religions as we do is making the same error. The tradition didn’t just emerge, it evolved from predecessors and it has descendants.

I did mention other and previous religions.
Religions themselves make it a point to distinguish themselves from the others, they have specific things that are sins.
Regardless if there are some taken over from the religions they stem from they DO NOT EXIST as sins from their own religion as it hasn't been invented yet.

It doesn’t care about what is “good” it only cares about what is most advantageous

Obviously, however we humans defined any trait that is most advntageous as good.
Humans needed the group to survive.
So it is good not to just kill someone or steal from them. Even if beneficial to the perpetrator.
Religion has appropriated many of these natural rules.
You are a good follower of religion X if you follow these rules, and breaking them is called a sin.
I see nothing that warrants calling these already existing concepts 'evolution'.

I also would never place religion in between "golden rule”, “religion”, philosophy, ethics, morality".

Religious and atheists are seperate cognitive sub-species who can choose to compete, fall into a predator-prey relationship (e.g. inquisition or communist religious purge) or we can coexist in our respective niches or, like all the best stuff in nature become symbiotic and male the system better for all.

Now this is a delusional.
History and present show religions are a huge danger and have awful consequences.
They are imperialist and invariably want to impose their world view.
Even if many of the followers don't necessarily want this, there are religious zealots that infect others.
Even if there wasn't any competition the religions try to impose their will on their subjects.

I couldn't care less what people believe, unless they start bothering others and this is what they do.
Allowing religion is like having a little fire that can get out of control at any moment.
If only sane people would be in charge (as I mentioned it is not the case due to the religious epidemic) it would be forbidden.
Just the same as cigarettes and alcohol if they would be if invented now.
The danger and damages are obvious.
It's like saying "I can do some cocaine and heroine, no problem. I'm a functioning member of society and no burden to society"
This can be the (individual's) case, but we know the consequences and examples and therefore do not tolerate this behavior in society.
It would be tolerated if a large portion of society were coke and heroine users.