The Austrian Inquisition
1585 A.D.: The now majority-Awesomenist Denmark renews war on Germany after hearing of a German inquisition against followers of Awesomeness in Hamburg.
Inquisitors are a Faith unit that remove religions other than the one you founded from your cities. Germany has been using them pretty aggressively to counter my missionaries.
A Swedish Great Prophet preaches his last sermon in the world metropolis of Vienna, and it quickly becomes majority Awesomenist. Massive tithes begin rolling in to the Swedish Church of Awesomeness from the teeming Viennese.
The Austrian Confucian upper class is displeased by this turn of events.
1595 A.D.: The Swedes and the Celts sign an open borders treaty, which would have been unthinkable 100 years ago.
The Austrian nobility denounce Sweden and the Church of Awesomeness, causing a rift in the Continental Alliance.
1610 A.D.: The Viennese institute an inquisition of their own, ridding Vienna of Awesomeness. Missionaries are immediately sent from Sweden to win it back.
1620 A.D.: Scholars at the Academy of Birka master chemistry, leading to huge advances in both the civilian and military sectors.
I can now build cannons, the first gunpowder siege weapons that become available. If a religious war breaks out with Austria, I'm fairly confident I could capture Vienna without much fuss. I'm going for Fertilizer next, which will improve all of my farms that don't have access to fresh water.