I finished Robert Grant's Gods and the One God.  In this post, I'll use as my starting-point something that Grant says on page 149 regarding the Holy Spirit:
"Some
 of the biblical texts treat 'spirit' not as personal but as a force, or
 even an experience, not clearly definable...The category of personal 
divine being shared by the Father and the Son is not quite the same as 
that shared with the Spirit, and this is one reason why Eastern theology
 speaks of the Spirit as 'proceeding from the Father' and in the West we
 hear of 'proceeding from the Father and the Son'... [But] we should not
 try to reduce doctrines to their presumed origins and assume that the 
nature of the Spirit must be limited to force or experience."
For better or for worse, Armstrongism
 has had an impact on how I study religion.  It's not that I assume that
 Armstrongism is the end-all-be-all of what the Bible means----far from 
it, for I neither associate with that movement anymore, nor do I follow 
many of its beliefs and practices.  But my background in Armstrongism 
does account for some of the questions that I ask, or some of the things
 that I notice when I am reading a scholarly book on religion.  Such 
questions include: "What did early Christianity believe was the proper 
relationship between Gentiles and the Torah?", and "Did the Hebrew Bible
 regard the Holy Spirit to be a person or an impersonal force----as in 
God's power."
On the latter question, Armstrongism maintained that
 the Holy Spirit was God's power, not a person.  What that means is that
 Armstrongism does not believe in the Trinity, and that is a big reason 
that it has been treated as an unorthodox cult by many conservative 
Christians.  Many may ask why it even matters----why should 
Armstrongites be so insistent that the Holy Spirit is an impersonal 
force rather than a person, and why should the "orthodox" boldly contend
 that the Holy Spirit is a person and not an impersonal force?  I mean, 
how many poor people does this debate feed?  Personally, I can 
understand why a person could look at this debate and consider it to be a
 non-issue.  I think that many of the doctrinal hang-ups of Armstrongism
 were rooted in a desire among people to feel as if they had more 
insight than others.  I myself tend to harp on these issues for a 
variety of reasons----my rebellion against what I was told was the only 
legitimate way to see things, or my curiosity about the extent to which 
Armstrongism is right or wrong.  For me personally, though, the debate 
does not matter a great deal, but I do find it interesting----and one of
 my goals as a budding scholar of religion is to find something 
interesting about which I can write.
So what is my stance about 
whether or not the Holy Spirit is a person?  I think that, from the 
outset, it's important for me to clarify something: I do not believe 
that the entire Bible is a thoroughly consistent document that teaches 
one position on certain doctrinal issues.  Rather, my impression is that
 the Bible is a diverse document and contains a variety of 
perspectives.  You can do with that what you wish.  Personally, I've not
 found a way to uphold the Bible as divinely-inspired while maintaining 
that view, but that doesn't mean that there isn't a way.  But I'm saying
 this because it's what sets me apart from Armstrongites and many of 
their conservative Christian detractors: both sides assume that the 
Bible is one consistent document from beginning to end, and I don't 
think that's necessarily the case.
So what about the Holy Spirit? 
 I'll just lay out what I currently think, but I will not rigorously 
defend it, at least not in this post.  I believe that, within the Hebrew
 Bible, the Holy Spirit is God's power.  That view could have carried 
over into Jesus' perspective during his ministry, since Jesus calls the 
Holy Spirit the finger of God (Luke 11:20).  But, at some point within 
the New Testament, the Holy Spirit was held to be a person.  When Jesus 
in Matthew 28 talks about being baptized in the name of the Father, the 
Son, and the Holy Spirit, that sounds rather Trinitarian to me.  And 
when Paul says in Romans 8 that the Spirit intercedes for believers who 
pray, he seems to be doing more than personifying an impersonal force: 
rather, he appears to be describing a person who intercedes.  James Dunn
 argues that Proverbs 8 personifies wisdom, which was deemed to be 
impersonal, and Dunn says this because (according to him) the Hebrew 
Bible was rather monotheistic; but elements of the New Testament go a 
step further and say that wisdom was a personal being, Jesus Christ.  I 
think that something similar is going on with the Holy Spirit----what 
was once considered to be an impersonal force becomes a person.