In the bible, it says that God created the earth and man and saw that it was good. But, when God created man he gave him free will. God gave man the ability to choose whether to do good or evil. This was so that humans would not be slaves. We can choose whether to follow God or not. So humans are the only ones to blame for their own decisions.
In a very indirect way religious figures can carry some blame because some of the violence and shunning of certain groups is due to religious interpretations of text, but it's doubtful that there's a higher being that is making anything good or bad happen. When humans do good or bad towards one another, it's because they chose to.