Bithynia (Βιθυνία) was a Roman province in the northwestern corner of Asia Minor (modern northern Turkey), bordering the Black Sea. It appears in Acts 16:7 when the Spirit of Jesus prevented Paul and Silas from entering it, and in 1 Peter 1:1 where Peter addresses believers scattered there.
The "Spirit of Jesus" preventing Paul from entering Bithynia (Acts 16:7) demonstrates a profound truth: God's redirections are not denials but divine guidance to greater harvest. That same night Paul received the Macedonian vision, and the gospel entered Europe. What seemed like a closed door was the Spirit steering toward Greece, Rome, and ultimately the Western world. Meanwhile, 1 Peter 1:1 reveals that Bithynia DID receive the gospel — just through a different apostle. God's word will not return empty; the method may change but the mission advances.