@Brahumbug
Moses for example is almost certainly a mystical character
"If you believed Moses, you would believe me, for he wrote about me. But since you do not believe what he wrote, how are you going to believe what I say?” JC
As for 'believe in Jesus', we haven't established that such a belief is necessary or required as the evidence for that position is distinctly lacking.
I'm not sure what you mean by this - could you expand please?
- doesn't say oh by the way owning another person as property is wrong.
It was already an established practice long before the time of Moses. If God had forbidden it completely, what would you suggest as an alternative to paying off debts etc? Selling all their possessions, leaving them unable to buy food and starving, selling themselves and/or their loved ones into slavery within foreign nations, criminal behaviour, prostitution? Slavery within Israel at the time was different to slavery as we might recognise it today.
https://www.gotquestions.org/Bible-slavery.html
Look at Egyptians' treatment of the Hebrews in the book of Exodus. These regulations would have been a radical change for the time period in which they were given.