I normally don't tolerate discussion of "Oneness" theology on my blog, i.e. in the comment boxes. However, there seems to be some interest in it of late from some of my commenters, so I'll offer a challenge to Oneness advocates, that they are free to answer in the comment box of this blog post. And, of course, my Trinitarian commenters are also free to provide their own challenges to Oneness theology, especially if they think they have something better than mine.
I will say this first, I don't pretend to be an expert on the Oneness view - and there may be more than one "Oneness view" about some of the Bible verses that I think contradict Oneness theology, or at least some possible form of Oneness Theology. I assume that Oneness theologians will acknowledge the authority of the Bible. I hope that they will seriously consider the implications of the passages below.
Here are two such passages (from the same chapter):
1) John 17:1-6
These words spake Jesus, and lifted up his eyes to heaven, and said, Father, the hour is come; glorify thy Son, that thy Son also may glorify thee: as thou hast given him power over all flesh, that he should give eternal life to as many as thou hast given him. And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent. I have glorified thee on the earth: I have finished the work which thou gavest me to do. And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was. I have manifested thy name unto the men which thou gavest me out of the world: thine they were, and thou gavest them me; and they have kept thy word.
2) John 17:21-26
That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me. And the glory which thou gavest me I have given them; that they may be one, even as we are one: I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me. Father, I will that they also, whom thou hast given me, be with me where I am; that they may behold my glory, which thou hast given me: for thou lovedst me before the foundation of the world. O righteous Father, the world hath not known thee: but I have known thee, and these have known that thou hast sent me. And I have declared unto them thy name, and will declare it: that the love wherewith thou hast loved me may be in them, and I in them.
It seems to me that these two passages (from the same chapter) are a significant obstacle to Oneness Theology for the following reasons:
a) It seems obvious that Jesus is praying to someone who is not Jesus, namely the Father. The Father is not Jesus. Therefore, while the Father and Jesus may be one in some sense (see John 17:21, for example), they are not one in another sense.
b) The sense on which they are not one is the sense of personhood. They are not one person. By "person" I don't mean "human being," since (for example) an angel is a "person" without being a human being, and God is three persons (Father, Son, and Holy Ghost) in one divine being.
c) One proof of (b) is the love of the Father for the Son. Love is a very personal attitude.
d) Moreover, the Father loved the Son before Creation. This means that persons of the Trinity are not simply modes of God - they are not God revealing himself to man in different ways (sometimes as a Father, sometimes as a Son). Instead, the persons have real distinction and real relation to one another, such that before the foundation of the world, they had love for one another.
e) Additionally, the Son had glory before Creation. This rules out any view that Jesus is simply a man somehow divinized by God abiding in him, such that Jesus only speaks to the Father as a man speaks to God and not as God speaks to God.
So, the challenge to any advocates of Oneness Theology is to make sense of John 17, while addressing the issues identified in (a)-(e).
Caveat: I'm interested in hearing what the Oneness answer to this challenge is. I think I've set up the challenge so that the challenge is not "why not Trinitarianism." That's not the challenge.