"Therefore," Paul begins 1 Corinthians 8:4, concluding what preceded this verse. The first three verses of chapter eight establish the ground or basis of what follows. Because our love of God is based upon our mutual covenantal faithfulness, God's covenantal faithfulness toward us and our covenantal faithfulness toward God, a faithfulness that impacts everything that we say and do as Christians, then that covenantal faithfulness must also guide our approach and behavior with regard to the holiday festivities previously mentioned.
The Corinthians had been invited to attend certain holiday festivities where the food served had been blessed or consecrated to other gods. It had been "offered to idols" (1 Corinthians 8:4). Should faithful Christians eat such food and participate in such events or not?
Paul responded by reminding the Corinthians that the idols in question were not real. They were not gods at all. They were false gods, illusions of the mind, imaginary. Thus, they had no real power or effect in the world. They were nothing. The God of Scripture is the only real God.
1 Corinthians 8:5-6 are understood to be parenthetical explanations of how it is that the world proclaims that there are many Gods, whereas Scripture proclaims that there is only one God who is Trinitarian. Verse 5 tells us two important things. First, that the many gods of the Greek and Roman pantheons are merely "so-called gods." They are gods only in name, but not in function or power. And secondly, that of these so-called gods "there are many ... and many 'lords.'" Many people are involved in the authority structures of these so-called gods. But in spite of all of this, Christians know that there is only one true God. Those who worship other gods are mistaken.
When Paul said, "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" (1 Corinthians 8:6), he did not mean that there is one God for Christians and many gods for other people. He did not mean that it was true for Christians to believe in one God and that it was true for others to believe in many gods. He was not speaking relatively. Paul meant that for those who understand the truth -- Christians -- there is only one God, the God of Scripture.
The remainder of Paul's sentence tells us that we exist for God, for God's purposes and not our own. And that we exist through God, through Jesus Christ. He equates God and Jesus Christ and says that they are one. And that our own lives have been created by God and for God. We are not our own. In chapter six Paul said, "do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body" (1 Corinthians 6:19-20). We belong to God, and God does with us whatever He desires (Romans 9:18).
Christians are not free
Christians are not free in the sense that they can do whatever they want. And Christians are free to want what God wants for them. We are free to be what God has created us to be. We are free to do what God wants us to do. But we are not our own, but are owned by Another.
We cannot improve upon God's creation. At best we can be what God has called us to be in Christ. And through Christ we can work to eliminate sin, but only as we participate in God's redemption plan. We cannot improve upon God's redemption.
All of this is to say that we must be who God has called us to be, do what God has called us to do, and worship as God has called us to worship. To do more or less is a function of faithlessness. We must remember Moses' injunction to God's people, for we are God's people:
"The Lord will open to you his good treasury, the heavens, to give the rain to your land in its season and to bless all the work of your hands. And you shall lend to many nations, but you shall not borrow. And the Lord will make you the head and not the tail, and you shall only go up and not down, if you obey the commandments of the Lord your God, which I command you today, being careful to do them, and if you do not turn aside from any of the words that I command you today, to the right hand or to the left, to go after other gods to serve them" (Deuteronomy 28:12-14).
The multiculturalism that we have been taught in school does not change any of this. Rather, it is simply a mark of our (American) unfaithfulness to the gifts that God has bestowed upon us.