Some more context on the verse I posted earlier. He was changing something he said earlier but it doesn't make it much better. Avoiding hypocrites isn't possible either.
1 Corinthians 5
9 I wrote to you in my letter not to associate with sexually immoral people 10 not at all meaning the people of this world who are immoral, or the greedy and swindlers, or idolaters. In that case you would have to leave this world. 11 But now I am writing to you that you must not associate with anyone who claims to be a brother or sister[c] but is sexually immoral or greedy, an idolater or slanderer, a drunkard or swindler. Do not even eat with such people.
This again, seems to underline the concept that if a person does not become saved, that we partake not in their life style.
The assumption here is that Jesus hung out with these types of people and didn't demand or perform some change in their lives. I think that would be out of character to assume Jesus would just sit around eating grapes why people talked about Mary's fine bust or round behind. Just doesn't make sense.
We also have to realize that Jesus was much more powerful than the people Paul is instructing in Corinthians, which by extension could include even us today. That if we are around people that live a certain life style that we know to be contrary to the wishes of God, one of two things happens. We begin to conform to their ways, or we become an outcast because we are unhappy being around that kind of people, because we don't approve of their choices.
So Paul rightly teaches, don't make your life with them.
This brings up a great and powerful point we haven't touched yet. Jesus, the Apostles, and a select other few, had special powers, that we simply don't have. They were directly sent, had power to kill, resurrect, do miracles etc...
Us, and the rest of people simply have their faith, their heart, their mind, and have to face the world. So it is not fair to think that Paul would go around telling people to hang out with sinners, because all will be well. Paul knew it would not be well, it would be tempting.
What Paul and Jesus left us with, are the tools to become more Christ like, by reflecting on life around us, reflecting on our own choices, and becoming a better person. We don't do this to get saved, or earn brownie points, it is just a perk or bonus we have in our daily walk with God.
As a result, I am sure there are people even today that can hang around sinners (like inmates at prison, or at strip clubs, etc...) and not be tempted, and try to spread the word.
Anyway, I hope this added some extra info for our discussion.