Dr. K.R. Allen said:
Steve the question you have asked, at least for your understanding of it, depends upon whether or not you believe the Holy Spirit to be Jesus Christ in the Spirit (Romans 8:1-17)? In your theology do you see the Holy Spirit as truly being one member of the Godhead? If not then the indwelling is disconnected from the true presence of Christ because of bifurcation in the doctrine. But if the Spirit is Christ then at what point does the Spirit indwell a person?
It also depends upon whether or not you believe in the doctrine of the present form of the kingdom yet also a future aspect of the kingdom to come. How do you view that?
It also depends upon whether or not you think Christ is still in his physical body and thus he is limited to one place at one time. If he is limited to one place at one time, due to his physical incarnation, then the Spirit is the key to the life here and the fullness of life there.
Combining those three points together we arrive at the idea that the indwelling of the Spirit is indeed a vivifying presence that is progressive and culminates in glorification. This would be linked to the doctrine of progressive sanctification. So is the union stronger in the future than in the beginning? Well, does true love grow fuller and fuller over time when it is the perfect love of the Lord? I would think our experience of it builds from here into eternity and forever more.