Means strictly a secret, and is so used when spoken of the heathen "mysteries" or secret rites, which were full of all manner of abominations. In the Scriptures the word "mystery" denotes those truths of religions which, without a revelation from God, would have remained unknown to man. Our Savior says to his disciples, that they are peculiarly happy, because God has revealed to them "the mysteries of the kingdom of heaven," Matthew 16:17 11:25 Luke 10:21-24. Paul explains the word in Ephesians 3:1-9; and often speaks of the mystery of the gospel, of the mystery of the cross of Christ, of the mystery of Christ which was unknown to former ages, of the mystery of the incarnation, the resurrection, etc., Romans 11:25 1 Corinthians 2:7-10 4:1 13:2 15:51 1 Timothy 3:9,16. These, then, were called mysteries, not only because they included some things which stretch beyond all human thought, and others which would never have been known if the Son of God and his Holy Spirit had not revealed them, but also because they were not opened indifferently to everyone; according to the advice of Christ to his apostles, "Give not that which is holy unto the dogs, neither cast ye your pearls before swine," 1 Corinthians 2:14. In one place "mystery" seems to denote the whole cycle of God’s secret plan in the administration of the gospel, gradually unfolded even to the end, Revelation 10:7 11:15.
Mystery signifies also an allegory, that is, a mode of information under which partial instruction is given, a partial discovery is made, but there is still a cover of some kind, which the persons who desires to know the whole must endeavor to remove. So the mystery of the seven star, Revelation 1:20, is an allegory representing the seven Asiatic churches under the symbol of seven burning lamps. So the mystery "Babylon the Great," is an allegorical representation of the spiritual Babylon, idolatry, spiritual fornication, etc., "I will tell thee the mystery of the woman;" that is, I will explain to thee the allegory of this figure, Revelation 17:5,7.