To be in Christ is to be functioning in your ministry (the Christ in you) in the Body of Christ.  This is all directed and powered by the Holy Spirit.  The Holy Spirit always leads according to the pattern of the Church as it is plainly given in Scripture.  God is in the process of purifying the Church.  He will deal with every false ministry, gift, office and ordinance.  He will purify our hearts.  He will bring us into holiness and finally into total redemption, even the redemption of our bodies.  He will place us into ruling authority if we are willing to be led into total holiness. The completeness of this redemption is beyond our ability to comprehend.

Jesus prayed that we "all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us." (John 17:21) He went on to pray that we may be one, even as Jesus and the Father are one, Jesus in us and the Father in Jesus, so that we may be made perfect (totally complete) in one. 

We have a pretty good understanding of what it is to have Jesus in us.  We know He dwells in unity with our spirits.  We can see plainly that we need to have Christ in us.  And we need to have Him fully formed in us. (Gal 4:19)

What does Jesus mean by: "they also may be one in us."  How can we be one in Jesus Christ and the Father? 

We desire to be found in Him. (Phil 3:9) We press toward the mark for the prize of the high calling of God in Christ Jesus. (verse 14) We are to grow up into Christ. (Eph 4:15) We are sanctified in Christ Jesus. (1Cor 1:2)  We pray that we don't remain babes in Christ. (1Cor 3:1) If we die, we join the dead in Christ. (1Cor 15:18) All these groups can be in Christ.  We can clearly see that we are to have Christ increasingly in us and we are to be increasingly in Him. We cannot do this, but God can do it in us.

We all need to discern and see the Body of Christ.  We see all the gifts, ministries, offices, and orders of the Church.  We also can discern and recognize the false.   Our identity is in Christ once we are born again.  That is, we have no purpose or meaning outside Christ the Body.  We are a member of Him.  He is a Body on earth and a Head in Heaven.  We are connected to our Head in Heaven and to His Body on earth.  Our life exists for the purpose of fitting into the Body as a member in particular.