You are…in the Spirit, if so be that the Spirit of God dwell in you…. and if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness. But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwells in you. (Rom. 8:9-11).
In God’s Word, different terms are often used to refer to the same Truth. Such is the case in this passage. Paul is here using terms that all refer to the indwelling of Christ in us through the Holy Spirit. He uses the terms, “in the Spirit;” “the Spirit of God;” “the Spirit of Christ;” “Christ be in you..the Spirit is life;” the Spirit of Him that raised up Jesus;” and, “His Spirit that dwells in you.”
Since Paul states in Ephesians that there is ONE SPIRIT, (Eph. 4:4) it means that all of these descriptions refer to that one Spirit.
This allows us to conclude that, “Christ in you,” means that we are joined to Him in by that same Spirit – i.e., our human spirit is joined to His Spirit – which is elsewhere named, “The Comforter,” or, of course, “the Holy Spirit”.
Why is this important? Because so often when we read that we receive the gift of the Holy Spirit, or that the Spirit dwells in us, we tend to focus upon the Spirit as something or someone separate from Christ – or as a FORCE that does things to us in our lives. This blurs and clouds the fact the Spirit in us means CHRIST IN US — that is, Christ dwells in us by the means of the Spirit of God. Indeed, the purpose of the Spirit of God is to reveal Christ TO us, IN us, and THROUGH us.