I recently had an email exchange with a neo-Marcionite (i.e., someone who essentially rejects the Old Testament wholistically as a witness to the true character of God). He argued that Jesus is not the God of the Old Testament, who ordered the destruction of the Canaanites, as I argued in another post, but only the Creator God. The Law of Moses, so he argued, was that of a man, not the Word of God. Hence, Jesus never argued that the He was the God of Moses who gave the Mosaic law, and thus, commanded the destruction of the Canaanites, as the Law of Moses does. Hence, Jesus refers to the law as "your law," instead of the God's Word (i.e., God's teaching/Torah).
Of course, if we can establish that, not only the Law of Moses, but the entire Old Testament is the Word of God from Jesus' own lips, then it should be good enough to settle the debate concerning what God Jesus is claiming to be.
Now, first we can say that simply from a lexical referential standpoint, when Jesus says, "God," He means the God of the Old Testament. They don't live in a pluralistic society that has multiple sources for their views of God. One might be able to argue that He is arguing for a correct interpretation of the God of the Old Testament, but one can hardly argue that He is attempting to refer to some other God other than that of the Old Testament.
But now, from His own lips, let's look at John 10:34-36.
Jesus answered, “Is it not written in your law, ‘I said, you are gods’? If those people to whom the word of God came were called ‘gods’ (and the scripture cannot be broken apart), do you say about the one whom the Father set apart and sent into the world, ‘You are blaspheming,’ because I said, ‘I AM one nature with God’?
There are three things I'd like to point out about this text that all come together to refute neo-Marcionism.
1. Jesus equates "your law" with "God's Word."
2. Jesus unites the entire Old Testament by using the least authoritative part of it (i.e., the Ketubim "Writings") and calling it the Word of God that is law and binding over the Jewish religious leaders to whom He is speaking.
3. Jesus states that the Scripture cannot be broken apart, which rejects their notion that some texts of Scripture are more authoritative than others, and therefore, supposedly lesser texts can be discarded rather than integrated into one's theology.
What this means is this: That Jesus is arguing that the entire Old Testament (even from what was considered least inspired) is one inspired Scripture that cannot be broken apart as any more or less God's Word than any other part of it.
Hence, Jesus is not claiming to be some other God than the one presented from taking the entire Old Testament together as a single picture of God. When Jesus calls Himself the I AM, He is referring to Himself as YHWH, the YHWH of Abraham, who destroys Sodom and Gomorrah, the YHWH of Moses, who orders the destruction of the Canaanites, the YHWH of Armies/Hosts, who wars against the wicked and decimates them, and the YHWH of Israel, who saves His people from others and from themselves.
For the Lord Jesus, there is only one God and only one reference that He would be signifying with His word "God." That is the God to whom Jesus testifies and with whom Jesus identifies Himself as One.