Jesus said in John 17:3 that it means everlasting life to know God (the Father) and also Jesus. So if the Holy Spirit really is God, then why isn't the Holy Spirit mentioned here as well? Further, why isn't the Holy Spirit mentioned in a whole host of other relative references in the Bible?
A good example:
If the Holy Spirit has always been God, and it means everlasting life to know God, then why would Jews instructed in the Old Testament scriptures and in the teachings of John the Baptist, not even know what the Holy Spirit was? (Acts 19:2)
If the Holy Spirit is God, then why is the Holy Spirit so vaguely described in the Bible? We know the Father's personal name ("Jehovah", Ps. 83:18; KJV) and we know the Son's personal name (Jesus). If it means everlasting life to know God, and if the Holy Spirit is God, then why doesn't the Holy Spirit have a personal name?
If the Holy Spirit is God, why does the Bible neglect to ever mention the words, "God, the Holy Spirit," or "The Holy Spirit is God"?
If the Holy Spirit is God, why does the Bible never mention a vision, dream or clear description wherein God and the Holy Spirit are shown as the same person?
The reason is because the Holy Spirit is not God and is God's active force:
"In the OT the Holy Spirit means a divine power..." -The Catholic Encyclopedia, p. 269, 1976
For much more, see the following:
Holy Spirit