Broken Vessels (Jars of Clay #2)
Lee Strauss

Based on a true story
With no way to prevent Helena from marrying another, Lucius flees to Rome to seek his fortune and mend his broken heart.
In a loveless marriage with a child to care for, Helena finds comfort in the most unlikely place--with her brother amongst the Christians. The religious group is mostly ignored by the Pagan populace, until the Emperor returns to the city and celebrations are planned. There's a shortages of criminals for the games and Christians are now sought out for arrest.
Fate brings Lucius back to Carthage, where his only wish is that he will get a glimpse of the girl he still loves. But when he finally sees Helena, it's under the worse possible circumstance...