What does Acts 16:29 mean?

It is sometime in the middle of the night in Philippi, a Roman outpost. Paul and Silas had been accused of encouraging the worship of Jesus, a faith not legally endorsed by the Roman Empire. In response, a crowd attacked them and the city magistrates ordered them beaten with iron rods and imprisoned (Acts 16:20–24). As with most crimes that do not warrant execution, the magistrates plan on exiling them in the morning (Acts 16:35).

In prison, Paul and Silas do not let their pain or their situation determine their outlook. They sing hymns of praise to God and pray while the other prisoners sit and listen. Suddenly, the earth shakes, the cell doors open, and the shackles come unlocked (Acts 16:25–26). When the jailer realizes what has happened, he draws his sword; allowing prisoners to escape is a capital offense, and it is better to die of one's own hand than to risk crucifixion (Acts 12:18–19; 16:25–27).

But Paul cries out in reassurance: the prisoners have all remained (Acts 16:28). Incredulous, the jailer submits to his prisoners. He has heard these two have been preaching about salvation through a Christ. He now believes them. He and his household receive their words and see to their wounds (Acts 16:30–34).

Paul and Silas started their stay in Philippi by bringing one Gentile woman and her household to Christ (Acts 16:14–15). Their last night, they watch a jailer and his family follow (Acts 16:32–34). For some reason, Philippi becomes one of the strongest churches of Paul's ministry, even supporting him as he ministers to other churches (Philippians 4:14–16). No one is beyond the Holy Spirit's grasp, and no one is too "other" to serve God's kingdom.