There is One God and One Christ Jesus - 1 Corinthians 8-9.

Now concerning things offered to idols: We know that we all have knowledge. Knowledge puffs up, but love edifies. And if anyone thinks that he knows anything, he knows nothing yet as he ought to know. But if anyone loves God, this one is known by Him. For even if there are so-called gods, whether in heaven or on earth (as there are many gods and many lords), yet for us there is one God, the Father, of whom are all things, and we for Him; and one Lord Jesus Christ, through whom are all things, and through whom we live. Am I not an apostle? Am I not free? Have I not seen Jesus Christ our Lord? Are you not my work in the Lord? Even so the Lord has commanded that those who preach the gospel should live from the gospel. For if I preach the gospel, I have nothing to boast of, for necessity is laid upon me; yes, woe is me if I do not preach the gospel! For if I do this willingly, I have a reward; but if against my will, I have been entrusted with a stewardship. What is my reward then? That when I preach the gospel, I may present the gospel of Christ without charge, that I may not abuse my authority in the gospel. Therefore I run thus: not with uncertainty. Thus I fight: not as one who beats the air. But I discipline my body and bring it into subjection, lest, when I have preached to others, I myself should become disqualified.
1 Corinthians 8:1-3,5-6,9:1,14,16-18,26-27 - hNKJV