In fairness, the Old Testament is a record of early Judaism more than Christianity, and a lot of it was written as Jews were persecuted and driven here and there and also fought for their survival against different religious groups of the time period, because going from polytheism to monotheism is apparently a scary prospect. (Also, not having to offer sacrifices to ask your god for salvation made the poor just as likely to go to paradise as the rich was not something that established powers liked the sound of.)