False teachers speak a mother-tongue
With that in mind read 1 John 4:5.
5 They are from the world; therefore they speak from the world, and the world listens to them. (1 John 4:5–ESV)
Here John is speaking about the false teachers. They came from the world into the church (just like we all do), but they preferred their old ways and never accepted the entire message of Jesus Christ. Eventually, they left the church, but being of a religious, evangelistic persuasion went out and taught an amalgam of spiritual concepts that jived with their first language, their spiritual mother-tongue. The world listened to their analogies, descriptions, explanations and found that a certain resonance was there. The false perspectives made some sense.
All people have their own opinions dangling around their necks. When those who would end up being the false teachers of John’s day joined the church, they never took those personal, opinion-necklaces off. They lived among the converted assimilating parts and pieces of the gospel that appealed to their notions about life. Clearly, there were some things about the gospel that attracted them. That draw, however, was only strong enough to get them in the door. It never resulted in the submission to God, that is, to their salvation. They never took their belief-necklaces off.
As a house divided against itself cannot carry on at some point, a break was bound to happen. When it did the false teachers left the church, and they, being from the world, spoke the world’s language. They proclaimed the appealing parts of John’s message, and as that was consistent with the first language of many people (some inside, most outside of the church), they made inroads into the church culture which had been growing up. Some people left the church to join with these splinters. Other, unchurched folk joined the fledgling pseudo-churches.
That was what was happening in the church-culture of John’s day. It should not be surprising that the unsaved happily embrace anti-Christian thought. People cannot hear God’s ways and means without the Holy Spirit.
Don’t wring your hands in doubt
When I observed my resident and a patient chatting at great velocity in Spanish I got a little jealous. I used to study some languages, and have a little German, Spanish, and even Swahili. The problem lies with my aspirations. See I want to speak so well that a native speaker must look at me to realize I am not of their background. I don’t study languages anymore; neither my aspirations nor even rudimentary fluency (self-contradictory?) ever happened.
John told his readers that they should not be surprised that many listen to the false teachers. The unsanctified will hear and understand what the false teachers offer. These teachers are good at what they do, and many respond favorably to false offerings. Worried Christians should not wring their hands when some people buy the spiritual goods others offer. Fearful Christians should not doubt the reality of the message or their salvation when they see the unsaved listen to false messages. “Live up to what you have believed. Ask God for help in belief.” These things work.