It is a mystery.  I love mysteries; the excitement is uncovering them.  As we seek God, we will uncover the hidden things of our Lord.  

“Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:   To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:” Col 1:26-27

Now this is a great unveiling, and it is for those who have been sanctified in Christ Jesus, made Holy (His saints). 

“But if Christ is in you, then even though your body is subject to death because of sin, the Spirit gives life because of righteousness”. Romans 8:10

Through the work that Jesus did on the cross, we are made alive in Him; we are Holy, blameless and righteous.