To some people, the Holy Spirit is simply one of God’s powers. In some or other vague way, this power has an effect on people’s lives and can be taken out like a “spare wheel” and used when the need arises.
To others, the Holy Spirit proceeds from God, but nothing more than that. Many Christians declare with great certainty that in their spiritual life they have knowledge of the Father and the Son. They testify to a relationship with the Father and the Son. They know the Father and experience His faithful care, and His love is a reality to them. They further confirm that they know Jesus Christ as their Redeemer and Savior and know that He died on the cross for their sins and guilt.
In effect, they do not believe in a Holy Trinity, but in a “Duality”. To them, the Holy Spirit is simply a biblical concept. They don’t deny the existence of the Holy Spirit, but they are unable to present any evidence of a specific relationship with or experience of Him.
In other words, such Christians not only have limited knowledge of the Holy Spirit, but also very little experience of His Presence and powerful functioning. The Holy Spirit is a vague unreality in their lives. The Holy Spirit is the Third Person of the Holy Trinity: one Being, but three Persons. God is three, and yet He is one.
The Holy Trinity remains an inconceivable mystery to us, but we see in the Scriptures that this is the way God reveals Himself. The Holy Spirit is not a mere power or influence of God, but a clearly visible, actual Person in the Godhead.
The Holy Spirit exists in a special relationship with the Father and with Christ . . . The Holy Spirit is the Spirit of the Father as well as of the Son, and confirms the unity between the Father and the Son.