The Holy Spirit is as much God as The Father and Jesus. The reasons for this are because He's called God, credited with the things God alone has done, does the sort of things only God does, and is given the same status by which we identify Jesus as God. The Holy Spirit is not Jesus or the Father because He is distinguished from them, send by them, and serves purposes in the world that aren't performed by the Son or Father.

1. The Holy Spirit is referred to rightfully as God through His unique characteristics that only God has.
2. The Holy Spirit is the most involved member of the Trinity in the lives of believers.
3. The Holy Spirit is distinguished from the Father and Son.