yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live. (NIV)
yet for us there is one God, the Father, from whom are all things and for whom we exist, and one Lord, Jesus Christ, through whom are all things and through whom we exist. (NRSV)
I have taken the liberty of putting every word which the Greek text does not include in bold italic. When there is no verb the interpreter has to decide what is intended. Is it simply an equative construction that is establishing a general relationship between the subject and object, or is there a verb implied by the context, or is it an ellipsis (missing verb) that indicates a well know saying where the verb does not need to be supplied because the original reader already knows the saying? 1 Corinthians 8:6 could be translated,
but for us one God, The Father, out from whom everything and us into him, and one Lord, Jesus Christ, through whom everything and us through him. (my rough trans.)Which makes quite a bit of sense even without those verbs, and even perhaps makes a different sense once deprived of those verbs. It sounds now possibly like a statement of theosis. You might then interpret it to be saying, "Everything has come from God, and our destiny is to become like him. Everything that is came from God through Christ and it is through Christ that we will become like God."
In the context of 1 Corinthians 8 and its discussion of idolatry this makes as much sense as the other interpretations. It is then not just that God is the only god because he is the only creator but also that he is the only God because he is the only god with whom we anticipate union through Christ.
Let me know what you think :-)