I think it’s important for us to make a distinction between judging BELIEVERS and judging NON-BELIEVERS.
That passage in I Corinthians 5 makes the distinction. "I wrote you in my letter not to associate with immoral people. I did not at all mean with the immoral people of this world, or with the covetous and swindlers, or with idolaters, for then you would have to go out of the world. But actually, I wrote to you not to associate with any so-called BROTHER if he should be an immoral person…
I also think we have to determine just what “associating with” means.
I think it’s clear that we are to associate with non-believers, even sinners, because that’s how we give witness to them of our faith and of Jesus Christ. WE are Jesus to them.
But it says that we aren’t to associate with believers who practice sin.
To me, a person who claims to be a Christian and comes to church and gets involved with the Church, but still practices immorality or stealing, etc. is someone that I should have nothing to do with. Of course I will nod politely and wave to that person when I see them at church. That’s just being polite. But I will not go out with that person, or invite them to my house, or go to their house.
And then there are those Christians who have fallen away and are estranged from the Church. James 5:19-20 makes it clear that we are to work to rescue those who have strayed from the faith. So I would say, YES, we should associate with these people.
Does this all make sense?