"God" has a name. A family name so to speak. We don't know what it is exactly. The KJV translates it "LORD". Some pronounce is Yahweh, or Jehovah. The point is that it IS the name of God. It means, in Hebrew, "the self existent", or "the eternal."
In the simplest terms, God and Christ are "one" in the sense that a man and wife become one at marriage. In a perfect marriage there is a man and a woman and they are one in thought, desire, aims and goals, yet two distinct beings. In the biblical model:
Joh 15:10 If ye keep my commandments, ye shall abide in my love; even as I have kept my Father's commandments, and abide in his love.
Joh 14:9 Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Show us the Father?
In other words, the father and the son agree completely. They are in perfect unity, perfect oneness of aims and goal.
This name, Yahweh (or whatever, we don't know) the mighty ones (elohim), is expressed "The Lord God." They are one. If my last name is "Smith" and I'm married, then we are known as "The Smiths". Same with God. Seems simple, but that's why God created man and wife...to not only express the marriage of Christ to church, but to show the relationship of the son and the father.
How would this teaching be different than "two gods who are married"?