He that touches pitch shall be defiled therewith; and he that has fellowship with a proud man shall be like to him.
Read Chapter 13
Cyril of Alexandria
We who have been justified in Christ, who, through faith in him, have obtained communion with the Holy Spirit, must be careful not to mix with those of perverse mind and impious spirit who do not have the true faith. They are in fact foreigners; they speak a different language and say perverse things. If someone mixes with them, he too will be contaminated, since it is written, "One who handles pitch blackens his hand." Therefore, if it is possible to bear fruit in the churches of Christ, why would anyone want to associate with those on the fringe or have anything to do with the impure congregations, provoking against oneself the God of the universe? - "Commentary on Malachi 2"