It started with this sect of people many thousands of years ago. They began to slaughter, rape, create slaves, and committed many other atrocities. When questioned they said that they had their god Adonai on their side. Using Adonai's name they began to grow in numbers and when people refused to join them, they simply killed them. When the original founders and their followers had children, they taught their kids about Adonai and then the cycle repeated. They became so good at teaching children about Adonai that they this cult's children never questioned Adonai for they either were convinced he existed or because they feared their families reaction. This repeated for hundreds upon hundreds of years.
Over time they changed of course. The books of Adonai were written time after time and caused quite a bit of confusion and at some points utter lying and forgery. Eventually the modern world came around, but they didn't want to change. Eventually they were defeated, but they only stopped when they were instead killed, imprisoned, or worse: expelled. Over the millennia they called their lord many different names, but today they settle under one: Jehovah, Yahweh, or God. They call themselves Christians now.
He teaches at my university, he got something wrong in a lecture once and thought he'd disproven Einstein theory of relativity until a first year corrected him
None of what you just said is true