I. The church is the mystery of Christ
"That their hearts may be comforted, they being knit together in love and unto all the riches of the full assurance of understanding, unto the full knowledge of the mystery of God, Christ," --Colossians 2:2
"That by revelation the mystery was made known to me, as I have written previously in brief, By which, in reading it, you can perceive my understanding in the mystery of Christ, Which in other generations was not made known to the sons of men, as it has now been revealed to His holy apostles and prophets in spirit, That in Christ Jesus the Gentiles are fellow heirs and fellow members of the Body and fellow partakers of the promise through the gospel," --Ephesians 3:3-6
"For this cause a man shall leave his father and mother and shall be joined to his wife, and the two shall be one flesh. This mystery is great, but I speak with regard to Christ and the church." --Ephesians 5:31-32