"For even if there are so-called gods whether in heaven or on earth, as indeed there are many gods and many lords."
This is clearly a reference to the idols of this world, as Paul in discussing matters of Christian liberty says many so-called gods. Anything can become a false god if whatever hypothetical object takes over our lives. The preceding and succeeding verses spell the point out emphatically:
"Therefore concerning the eating of things sacrificed to idols, we know that there is no such thing as an idol in the world, and that there is no God but one." (v. 4)
"yet for us there is but one God, the Father, from whom are all things and we exist for Him; and one Lord, Jesus Christ, by whom are all things, and we exist through Him." (v. 6)
The inspired writer makes a creedal statement in his exclusively affirming Christianity to be the truth. In so doing, he rules out the idea of men striving to become gods in the afterlife because he says that there is only one God. Thus, Mormon apologists have made an argument that backfires.
The uniform testimony of Scripture is that there is only one God (Deuteronomy 4:35-39; 2 Samuel 7:22; 2 Kings 19:15; 1 Chronicles 17:20; 1 Timothy 1:17; James 2:19). There is no other besides Him.
The idea that God the Father was once a mortal man who worked to obtain His position of deity is contradicted by Scripture because it says that He is eternal (Psalm 90:2).