[Amnorix]

Side note on this plotline -- the books did a really good job of developing it a bit more than what the show has been able to do, largely due to time constraints. It was an interesting social commentary too.

The Faith Militant (the military arm of the church) had been banned a long time ago by the Targaryens because, as much as anythign else, they couldn't control it. In the aftermath of the economic devastation of the civil war, which greatly affected food and other supplies coming into King's Landing, and then the siege, widespread suffering, starvation, death, disease and devastation was the result. In their time of trouble, many turned to religion, and zealots and radicals became increasingly powerful within the church hierarchy.

And then, ultimately, as we've also seen in the show, Cercei allows the restoration of the Faith Militant.