Charles Spurgeon Commentary 2 Thessalonians 3:6

"Now we command you, brethren, in the name of our Lord Jesus Christ, that ye withdraw yourselves from every brother that walketh disorderly, and not after the tradition which they received of us." — 2 Thessalonians 3:6 (ASV)

Paul had been to Thessalonica and had given oral teaching, and now he commits to writing what he had spoken; but he instructs them to take care not to associate with those who wilfully broke the ordinances of the church which he had taught them. There are some brothers with whom it is harmful for us to associate, lest they harm us, and it is also harmful for them if we associate with them, lest we seem to assist them in their evil deeds.

This is especially true in the case of brothers of the kind that he is about to describe—mischief makers, troublers, people who can always tell you the gossip of a congregation, who can tear a neighbour's character to pieces, who are able to perceive spots on the sun; people who delight in parading the fault of God's own children, and are never so happy as when they are making others unhappy by what they have to spread. These are the kind of people to whom you should give a wide berth.