Paladin of Souls (2003)

Ista has good reasons to distrust the gods when she leaves home on pilgrimage. Possession and divine intervention make her freedom newly precarious: helping other people requires judgement about what she owes them, and what she may refuse. Bujold gives priests and lay believers individual temperaments, with affection and practical humour alongside the spiritual danger. Read The Curse of Chalion first for Ista's earlier history; this story centres her own agency.