The word 'Mystery' comes from the Greek word musteerion, and means 'secret.'  It occurs 27 times in the New Testament.  If one reads each of these references to the 'mystery' or 'secret' it becomes immediately obvious that there are several 'secrets' or 'mysteries' described in the Scriptures.

The 'Mystery' in the Gospels

            The three occurrences in the Gospels all refer to the "secrets of the kingdom of heaven" or the "secrets of the kingdom of God." (Mat 13:11; Mar. 4:11; Lu. 8:10).  In Matthew 13, after the Lord had spoken the parable of the sower his disciples asked a very pertinent question:

"And the disciples came, and said unto him, Why speakest thou unto them in parables?" (Mat. 13:10)

It has been incorrectly said that the Lord used parables to make His message easier to understand.  The exact opposite is true, and this is where Scripture defines the meaning of the word musteerion.

   "He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given.
   "For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath.
   "Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand." (Mat. 13:11-13)

But while the meaning of the parables was hidden, or 'kept secret,' from the crowds, it was plainly revealed to his disciples.

   "But blessed are your eyes, for they see: and your ears, for they hear.
   "For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them.
   "Hear ye therefore the parable of the sower." (Mat. 13:16-18)

        Thus we see that a 'mystery' or 'secret,' as defined by our Lord, is something hidden from the understanding of some, but plainly revealed to others.  Although the truth of the message was given to all, it was couched in a hidden form of communication that only certain individuals might understand, and these only when the parable was explained.  Why did the Lord Jesus hide his message?  Because the Lord was saying there are the "haves" and the "have nots."  There are the 'elect' and the 'non-elect.'

   "For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath.
   "Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand." (Mat. 13:12-13)

   "All these things spake Jesus unto the multitude in parables; and without a parable spake he not unto them:
   "That it might be fulfilled which was spoken by the prophet, saying, I will open my mouth in parables; I will utter things which have been kept secret from the foundation of the world." (Mat. 13:34-35)

The Mystery in the Apocalypse

        The word "mystery" or "secret" occurs 4 times in the Revelation.  In Revelation 1:10 the apostle John was shown a vision of the great and terrible "day of Jehovah."

  "I became in the Spirit in the Lord's day, and I heard behind me a great voice as of a trumpet." (Rev. 1:10)

        This first of many visions of Jehovah's day was of the One known as "the Alpha and the Omega, the First and the Last" (Rev. 1:11).  It was a vision of the mighty Judge of all the earth, the Lord Jesus Christ, depicting Him standing in the midst of seven lampstands, and holding in His right hand seven stars (Rev. 1:12-16).  The symbolism of the seven stars in the Lord's right hand is described as the 'mystery' or 'secret' of the seven stars.'  This 'secret'  meaning of the symbols is then revealed to John.

   "The mystery of the seven stars which thou hast seen on my right hand, and the seven golden lamps. -- The seven stars are angels of the seven assemblies; and the seven lamps are seven assemblies." (Rev. 1:20)

        Later in the book John sees another symbol

 the 'secret of God' (Rev. 10:7), and the 'secret, Babylon the Great' symbolized by the 'secret of the woman' (Rev.17:5 & 7).  The remaining 20 occurrences are in the Epistles of Paul.  None of the letters of Peter, James, John or Jude use the word.

The Mystery in the Letters of Paul