He had time to reflect on the experience and the lessons learned. Like Nelson Mandela, who spent 27 years in a South African prison, he learned that 1. Jail is awful. Personal nonviolence is crucial if you want to survive in jail. The Bible and communion with God can sustain us through anything.
Community is essential.
Christ is present among the prisoners. Go and visit the imprisoned. Jailers are human, too. Contemplative prayer is a basic requirement. Hope is granted in daily doses.