I agree that he is using the Gentiles as an example of how not to live,that was my point ,,,,but in in the next chapter , he says therefore ,, linking the next chapter ,which shows the context in which he was speaking ......
1Therefore be imitators of God, as beloved children; 2and walk in love, just as Christ also loved you and gave Himself up for us, an offering and a sacrifice to God as a fragrant aroma.
3But immorality or any impurity or greed must not even be named among you, as is proper among saints; 4and there must be no filthiness and silly talk, or coarse jesting, which are not fitting, but rather giving of thanks. 5For this you know with certainty, that no immoral or impure person or covetous man, who is an idolater, has an inheritance in the kingdom of Christ and God.
6Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience. 7Therefore do not be partakers with them; 8for you were formerly darkness, but now you are Light in the Lord; walk as children of Light 9(for the fruit of the Light consists in all goodness and righteousness and truth), 10trying to learn what is pleasing to the Lord. 11Do not participate in the unfruitful deeds of darkness, but instead even expose them; 12for it is disgraceful even to speak of the things which are done by them in secret. 13But all things become visible when they are exposed by the light, for everything that becomes visible is light.......
So when he says ,instead expose them ,it is clear that he is talking those Gentiles in the previous chapter ,,,,,what he means by expose them , is not entirely Clear.. .....
Weather it be through preaching ,or witnessing or warning others about the dreaded lifestyle ,or all three ,,,the teaching to expose them is the word of God weather it fits our ideas or not ........,it worth considering the rather then slinging rebukes at those who actually believe and practice this teaching ...... Not saying your doing that ,,,but Iv seen people do it here ,and some how they think they are better for not doing it ,,, a little aragent I think ....
God bless you too