Bible Word - 'Mystery'

In the New Testament, the 'mysteries' of the gospel are contrasted with the mysteries of the pagan religions of the first century Roman Empire. Those who joined pagan cults were, upon initiation, entrusted with secrets that they were not allowed to disclose, sometimes on pain of death. By contrast, God revealed His mysteries by the preaching of Christ and the apostles throughout the world. The most important 'revealed mystery' was that, in Christ, all the blessings of God formerly covenanted to Israel would be extended to those who were called by God out of the pagan world. No longer would such blessings be limited to Israel (see Ephesians 3:3-6).

"Now to Him who is able to establish you by my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery hidden for long ages past, but now revealed and made known through the prophetic writings by the command of the eternal God, so that all nations might believe and obey Him." (Romans 16:25-26).