Ever since Cersei Lannister empowered Jonathan Pryce's High Sparrow to take over the Sept, close the brothels, and scourge the wicked, I've been waiting for two problems to end his reign of terrifying purity.
First, once the wicked repent, he more or less has no choice but to forgive them, even if that means setting himself up for a second fight with a better-prepared foe. Second, he has no great lord's army keeping him safe, and the black-robed Faith Militant with their cudgels won't last long against actual armored troops.
Personally, I was sort of hoping the Lannisters would order the High Sparrow to be hung and burned, or maybe a trial by fire, because that's what happened to the his real-life precursor—the Friar Girolamo Savonarola in 15th-century Florence. Alas, the monk seems to have successfully won over Margaery Tyrell and King Tommen, so instead of being torn apart by a mob or a military force, the lead zealot let the queen off from her walk of atonement, faced down the Tyrell army, and found a partner on the throne.
Thus he saves his Faith Militant from righteous martyrdom, but also renders himself permanently political. So now we have #TeamHighSparrow vs #TeamJaime, or as the High Sparrow said, "A new holy alliance between the Crown and the Faith." I'm skeptical it will last beyond contact with the real world.