I have studied this topic academically, a little bit. My answer:
- The people who wrote the old testament lived in a world that was almost unfathomably dangerous and difficult compared to today's first world. Death, disease, starvation, natural disasters, the collapse of whole towns and settlements, unexplained daily suffering for which there is not even an explanation let alone a cure, were constantly present. If you're in that place, and you believe there's a God who's in charge of it all, there is absolutely no conclusion to come to other than he's a real son of a bitch.
- I definitely believe that Jesus had some kind of genuine religious inspiration, that a lot of what he was teaching was for-real insight about life. The stuff about forgiving your enemies, living for good works through action and how it really doesn't matter what you say or what team you're on, trying to build a better life by caring about people around you, taking care of the sick and injured, even if they are beggars or prostitutes or foreigners or otherwise "bad" people in your mind simply because of their circumstances, seems pretty spot on to me. It was 100% at odds with the religion of the day, pretty much as much as it is with modern religion. What Jesus actually said does obviously have "spiritual" and supernatural elements also, but it is also focused to a huge extent on what you as an individual can do, and a sort of alignment towards the greater good and a calling for humanity, as opposed to this wild half-Pagan mythology about a capricious and bad-tempered God who might kill you at any instant.