text: why do some preachers require a proof of income, before you can attend their church? two preachers that come to mind in los angeles are rev. fred price and bishop charles blake. for two reasons, they want to make sure that you are financally able to support their church and so that they don't have to support you financally because that's what churches are suppose to do is help their members in need and most don't want to have to do that.