The church certaintly wouldn't read that verse in the unitarian sense as Jews or even muslims would. Rather that verse is to be read in the sense of the trinity, and there is One God and he is a trinity. So verses like this don't help either side in establishing who has the right idea of God in the Old testament, rather we have to look for inferences as to God's personhood, and it seems to me in the Old testament, starting with genesis which has many verses implying a plurality of persons within God (let us create mankind in our image) or even verses in which the angel of the Lord directly speaks as if God, show us that there is a plurality within God.