Romans 8:29-30 For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified.

Created in the image of His Son, who is the express image of the Father, this is His intent of design, but it takes the third part to complete man into the triune image.

As I said before man has with his soul sought his creator.

Romans 8:19-20 Because that which may be known of God is manifest in them; for God hath shewed it unto them. 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; so that they are without excuse:

Now the Spirit is perfect in power, form and function. The Spirit is God and therefor does not suffer corruption. Once the Spirit is given by faith in the saving grace gift of His sacrificial life, a surrendered life is no longer our own, and we are subject to the power, purpose and presence of the Holy Spirit in use who are now triune beings.

The Holy Spirit as God does only the will of the Father, only testifies of Jesus Christ and serves within this temple body as a Comforter, Spirit of Truth, instructor, guide, and executor of all the promises of God in this New Testament.

All that while remaining God in the third person, perfect and Holy.

But how do we understand the Spirit? By the faith that was given, the faith that comes by the Word of God, and communicates the identity and character of God the Father and Jesus Christ. Faith is communication between the soul and the Spirit. This is how He makes Himself known.