Having laid out his sweeping argument based on God’s plan of salvation in history, Paul now turns to a more personal, emotional appeal.
8 Formerly, when you did not know God,
See Eph. 2:12. God was in covenant relationship with Israel but not the other nations, and in fact they had degenerated into pagan idolatry and were not in covenant relationship with God.
you were enslaved to those that by nature are not gods.
“Those that by nature are not gods” is Paul’s way of describing idol worship (see 1 Cor. 8:4-6). However, while Paul did not believe the pagan gods were real gods, he did believe there were real powers at work in idolatry – demons (1 Cor. 10:19-20).