Voice is about a Jewish (and Christian) slave girl who is captured during the fall of Jerusalem and ends up a slave for a Roman family. She ends up caring deeply for the family (especially the son!) but faces dire consequences for her faith. Tied in with her story is another slave-forced-to-be-a-gladiator. Rivers weaves numerous storylines together so well--it's definitely an epic story.
Rivers is a great writer....for proof of this, my younger sister, who didn't like reading (how are we even related???), read Rivers' Redeeming Love and suddenly discovered she liked reading!
This series is from the early 1990s but it's remained in print since then--clearly people like it. It's book one in a trilogy, so I'll post reviews about books two and three in the months to come.