I live in a Christian Country where people believe in God, goes to church ang always pray but crime rate is still high. Why? I think because of the extensive poverty that some people resort to robbery and killings plus the alcohol and drug related crimes. I have seen the priest and pastors doing their duties and responsibilities teaching the Gospel, visiting the prison and doing bible studies and all other missionary works but still humans have freewill and judgement. While I think religion can help creating ethical framework and a regulator for values in a day to day life but it is still enough to fight or reduce crimes and violence.
In some cases, religion enables and encourages discrimination and crimes against some people.
Religion can also be a good way to protect knowledge only if the people who're managing the books of those religious books are good and want the good of others.
Otherwise, they can misinterpret the lines written inside the books and make the sheep follow what servers them.
The second reason is what I think is going on.