God's grace restores failed people and reaches unlikely people.
Week 4 highlights two displays of mercy: God gives Jonah another shot, and God gives Nineveh a chance to repent. Don't rush past "the word of the Lord came to Jonah a second time"; that's not just forgiveness, that's recommissioning. Jonah preaches maybe the shortest sermon in Scripture, and an entire city turns. The power was never in his delivery. It was in God's word.