How else can we understand another person, unless we are close to them 'as a friend'? Wasn't Jesus said to be the friend of sinners, even though He did not sin? We are all sinners, therefore we are not better than anyone we see on the street. We have messed up and fallen short, just as badly or maybe worse than them, only God knows. So let's wear off this idea of isolating ourselves from "dangerous" unbelievers.
How would God think of this? Proudful heart, who just wants to save itself?
I think we must put ourselves at risk, for the sake of Christ. It's true that if someone is truly blasphemous, maybe it is best not to hang with them, or if someone can't stand you. Then it is better to sprinkle the sand off our shoes and walk away, like Bible commands.