Leaving the religious aspect of things aside for just a moment, have you ever considered that the 'religions' in fact provide a lot of services that the government doesn't.
If you start taxing 'religions' they would simply make budget cuts elsewhere and the unfortunate reality is this would be via services.
Your argument is a very populist arguement, but the real world reality is unless the government is going to fund a lot more in direct services then they would be silly to do it.
