As described in A Parallel Society, Jehovah’s Witnesses do not live in colonies or communes – but they are compelled to separate or isolate themselves from non-Jehovah’s Witnesses as much as possible. In addition to the references on that page, a few more references follow below.

The Watchtower magazine, September 1, 1974, page 516

“Put bluntly, while non-Witnesses can trust only their kin (and not always them), Witnesses can trust both kin and fellow Witnesses.”… there are no more honest people in the world than Jehovah’s Witnesses…A world filled with people like them would hardly need locks, would it?. ..Would it not be a pleasure to associate with such honest, peace-loving people?

The Watchtower magazine, September 15, 1987, page 12

So our challenge is to be in Satan’s world, yet being no part of it, to be surrounded by its contaminated “air,” yet not breathing it in. When we read secular publications, watch television, or go to places of entertainment, we are likely to be exposed to the world’s “air.” While some contact with worldly people is unavoidable​—at work, at school, and otherwise—​we must be vigilant so as to keep from being sucked back into the death-dealing atmosphere of this world.​

The Watchtower magazine, December 15, 1993, page 13

Our heavenly Father admonishes us: “Do not lean upon your own understanding.” (Proverbs 3:5) Worldly counselors and psychologists can never hope to approach the wisdom and understanding that Jehovah displays. “His understanding is beyond recounting.” (Psalm 147:5) Rather than lean on the wisdom of prominent men of the world or on our own uninformed emotions, let us look to Jehovah, his Word, and the elders in the Christian congregation for mature advice.

The Watchtower magazine, May 1, 2007, page 15

Consider an example. Are you an adult who is sincerely trying to make Jehovah’s heart rejoice? (Proverbs 27:11) If so, you are to be commended. But imagine for a moment that some workmates offer you a ticket to accompany them to a sporting event. They enjoy your companionship at work and would like to socialize with you outside the work environment. You might have the strong impression that these individuals are not bad people. They might even have some good principles. What will you do? Would there be any danger in accepting the invitation?

The Watchtower magazine, June 15, 2010, page 9

Today, the world is a dangerous place for Christians. (2 Tim. 3:1-5) Satan knows that his days are numbered, and he is out to devour the unwary. (1 Pet. 5:8; Rev. 12:12, 17) However, we are not without protection. Jehovah has provided his people with a safe spiritual refuge​—the Christian congregation…

That we simply cannot socialize with unbelievers and hope to suffer no ill consequences. The Scriptures state that “bad associations spoil useful habits.” (1 Cor. 15:33) On the other hand, association with people who share your beliefs, your high moral standards, and your love for Jehovah is a safeguard.

The Watchtower magazine, February 15, 2013, page 24

Of course, some contact with unbelievers​—such as at school, at work, and when sharing in the ministry—​is unavoidable. It is quite another matter, though, to socialize with them, even cultivating close friendships with them. Do we justify such association by saying that they have many good qualities? “Do not be misled,” warns the Bible. “Bad associations spoil useful habits.” (1 Cor. 15:33) Just as a small amount of pollution can contaminate clean water, friendship with those who do not practice godly devotion can contaminate our spirituality and lead us into adopting worldly viewpoints, dress, speech, and conduct.