Hi brother,
What is the difference between the Father who is spirit and the Spirit of God?
Part of your answer lies in what we can know of God through creation.
20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, [even] his eternal power and Godhead; (Rom 1).
Transfer Paul's statement to an earthly father, and you will see there is much more to fatherhood, than merely the son which comes forth from his flesh.
The Spirit of God therefore, may indeed be [u]all[/u] God, but as He pertains to the believer, we could not fully [i]contain[/i] [u]all[/u] of 'the Spirit of God'. Nevertheless, His effect on the believer is to bring forth the likeness of the Father, (God the Father), as a demonstration of the believer's sonship of God, or [i]in[/i] God.