Final answer:
Paul knew he would survive the journey to Rome because of a message from an angel of God assuring his safe arrival and that of his fellow voyagers.
Step-by-step explanation:
The Apostle Paul was confident that he would survive his journey to Rome because of his faith and a specific divine assurance. In the Acts of the Apostles, particularly in Acts 27, as Paul was sailing to Rome as a prisoner, the ship he was in encountered a severe storm. Paul received assurance from an angel of God, who told him that he must stand before Caesar and that God had graciously given him the lives of all who sailed with him (Acts 27:23-24). Thus, it was this divine message that provided him with the knowledge and faith that he and all the crew would survive the voyage despite the treacherous circumstances they faced.