How to tackle revolting Christians (Christian revolutions)

pcshogun-2-total-war

Two of my provinces are constantly spawning Christian rebels, these provinces are on the edge of my territory, bordering on my enemies territory.

Are there any steps I can take to stop this?

Could there be a spy or Shinobi in these provinces causing trouble.

UPDATE

My territory now pushes far past it's previous boundaries but these two provinces are still spawning Christian rebels.

Best Answer

I should have mentioned in my question, but the original offending province was Bungo.

Bungo has a nanban port, which provides +3.5 to Christianity in that province and once Christianity reaches 100, it spreads to the surrounding provinces. So I need to destroy that port and build me a nice Buddhist temple!