Religious organizations should be tax exempt because they are non-profit. The money that goes into these organizations is often returned to the surrounding area that they are located in to help those in need. It is often used for missionary work to help expand their beliefs and help impoverished areas.
Religious organizations should not be exempt from taxes because they often operate like a business. They collect money from member dues and tithing, while providing a service of entertainment at the church. In my opinion this is why they should also be required to pay taxes like any other business would too.