One thing that strikes me when reading through the NT is that it seems impossible to view the Holy Spirit as merely a force. The JW teaching is that it is sort of like God's magic. It causes things to happen. But when I read through the Bible, I get a very different picture of the Holy Spirit.
So I thought I'd make a comparison list of the WT teaching vs what I see the Bible teaching.
Watchtower: The holy spirit is not a person (note the lowercase letters)
The Bible: The Holy Spirit displays attributes that can only belong to a person with a personality. He has a mind (1 Cor 2:10) feels emotions (Eph 4:30) and has a will (1 Cor 12:11). He does things that only a person can do like pray (Romans 8:26) and speaking to people (John 15:26)
Watchtower: Because the holy spirit does not have a name, "it" is not a person.
The Bible: Literal Spirit beings are not always named in the Scriptures. In many cases they are identified by their character. Demons are called "wicked" or "unclean" spirits. In the same way, the Holy Spirit is identified by His holy character (John 16:7-14)
Watchtower: The Bible says that we must be "filled" with the holy spirit. This proves that the spirit is not a person.
The Bible: Eph 3:19 speaks of us being filled with God Himself. Obviously God is a person. Eph 4:10 also speaks of Christ filling all things. Obviously Christ too is a person. So is the Holy Spirit.
Watchtower: The Holy Spirit is never spoken of as being God, but instead is only God's impersonal "active force" for accomplishing His will in the world.
The Bible: The Holy Spirit is spoken of in the same terms as God is. He is called God in Acts 5:3,4. He also has all the attributes that God has. He is omnipresent (Psalm 139:7), omniscient (1Cor 2:10), and omnipotent (Romans 15:19)
In conclusion the Holy Spirit's own works confirm that He is a person. He teaches believers (Romans 8:14), He testifies (John 15:26), He guides believers (Romans 8:14), He commissions people to service (Acts 13:4), He issues commands (Acts 8:29), He restrains sin (Genesis 6:3), He prays for people (Romans 8:26), and He speaks to people (2 Peter 1:21). He can be grieved, blasphemed, lied to, obeyed, and sent. These terms would not be appropriate to apply to a mere force.
Maybe the most damning to the Watchtower (IMO) is that if the Holy Spirit is a force, as the WT argues, then why does the Holy Spirit use the personal pronouns "Me" and "I" in reference to Himself (Acts 13:2)?