What the Bible says about In the Flesh
(From Forerunner Commentary)
Are we already spirit? Well, the old hat pin test works very well here. This verse says, "You are . . . in the spirit, if so be that the Spirit of God dwells in you." "In" is not being used to state physical position, a physical location, but in the sense of concerned with. Paul uses it in the same sense as we would say, "He is in politics" - this person is concerned or involved with politics. A Christian's concern is with things of the Spirit of God, the mind of God. It is a matter of mind, attitude, thought, perspective, wisdom, knowledge, and direction of life. Jesus said, "He who seeks to save his life will lose it, and he who loses his life for My sake will find it." It is a matter of concern, involvement. That is what "in the spirit" is.
It is a matter of direction of life. It is the concept of spiritual relationships that dominate the correct understanding, not physical location in regard to Christ or the church, because those relationships can and do involve people of all races, all nationalities, physically located in all places on earth. But when one is "in the spirit," that person's great concern and involvement in life lies in his relationship with God. If one is "in the flesh," then his concern and involvement revolves around his relationship with the carnal world.
John W. Ritenbaugh
The Holy Spirit and the Trinity (Part Four)