Why is immorality always connected with pagan idolatry?
Immorality is always connected with pagan idolatry because it is satanically controlled. When people enter abject pagan idolatry or mythologies, rank immorality is part and parcel of it. Israel's golden calf worship was reduced to that same level, and the people became naked and immoral.
Les teaches that immorality accompanies pagan idolatry because the whole system is satanically controlled. He points out that in abject pagan idolatry, the mythologies, and the Greek gods, you always find rank immorality; it is just part and parcel of it. At Sinai, the golden calf worship was not merely casual dancing; the people were naked and immoral, having put that worship down to the level of all other idolatry. Les says this is the evidence, and Paul uses it to warn the Corinthians and us, since we are no different from them.