We read in the Old Testament that God created a nation that was supposed to be different from other nations and be his representative on the Earth. Part of the plan for that nation was to give them laws and regulations through which they should live and there is nothing unusual in that, every nation had laws. What is interesting and unusual is the countercultural nature of those laws.
For example, God told them that every seventh year they should cancel the debts of the debtors, let the captives go free, not glean the fruits of the harvest so the poor can eat and so on. Basically God wanted everyone to be provided for. Not the rich to get richer and the poor to get poorer. If that was ever worked out practically it's another question.
Also, all through the Bible God speaks against usury, taking financial advantage of those who are in bad situation and need to borrow money, meaning giving them money that needs to be payed back with interest.
But what about the banks in our modern society? What about the way they work and the foundations they are built upon? They are such a normal part of our urban life that we fail to see on which foundations they are built. Their basic function is to lend people money and take it back with interest.
Christians would say that some jobs are not suited for those who follow Jesus. Let's say that christians should not work in sex-shops, casinos, strip-clubs, and that's ok. But what about banks? When we hear that someone works in a bank do we see him as an achieving person, a person with a good job, or a person who serves the spirit of money and greed? I'm not giving any conclusions here, I'm just asking.