It is because most people in history, those not in authority, were illiterate so that those who could write told the peasants that their written word was sacred...........what a con trick!
For example who says that the law was hung on the torture stake?
Well it was written by the leaders of the early Jesus cult which was in the process of adopting and adapting all forms of religious belief to create is own orthodoxy. This included apostate Jews who had fallen for the latest "Christ" story fictions, by bishops who wanted numerical support for their movement--because more members made for more money in the coffers and lots of money meant political power.
Remember that the early Christians met not only in houses but in temples and used exactly the same hierarchical orders and religious organisational methods as the groups who were later to be condemned by the RC Church as "pagans". The Bible gives an extreme partisan view of Christian events in the early centuries including a conjectured account of the Christ hero, magical happenings and a sanitised account of its own history with the emphasis on divine blessing for itself and a bunch of failed prophecies.
The legacy of which is a devilish distortion of reality in the minds of millions right up until now!