Loans have happened long before 2008 and have continued ever since.

This process is described in the Bible for example!

What does the Bible say about collecting interest on loans (the necessary part for making mortgage backed securities)

"Do not charge your brother interest on money, food, or any other type of loan. You may charge a foreigner interest, but not your brother." - Deuteronomy 23:19-20

I also like Ezekiel 18:13

I sort of would read bible passages describing modern financial instruments.

Perhaps it has some psalms discussing merits of MMT, or parables on Quantitative Easing.