The idea
Currently, money made by religions does not have tax. This is wrong. It is quite clear that some religions are run like businesses, and that this tax-exempt status merely helps rob the country and put more money into the hands of the rich.
The Archbishop of Canterbury lives in a palace, and owns two other homes. It is clearly wrong that he should have bought these homes with money that was tax-less.
We need to be secular, and stop pandering to religions.
Why is it important?
Raises more money for the government, and stops it being stolen by religious leaders.