I think this is a good question to ask when you are thinking about a Christian business. What does that really mean. Some people think you need to have a business that sells Christian books and paraphernalia, others think this type of business should not make a profit because that is bad somehow.
I think saying you have a Christian business means you live by the teaching of Jesus Christ. I think you do your best to serve your customer. You should not take advantage of your customers but you need to run a profitable business to support your self and your tithing.
There is nothing wrong with making a reasonable profit because ultimately that profit will do two things. It will allow you to make your business better and it will support your family. Both of these are honorable things to do. A better business can help to support your community that much better.