Shared ground
These verses describe a real change followed by a real reversal. The people in view had “escaped” the world’s defiling patterns through knowing Jesus Christ, then became entangled again and were “overcome” by what they left (2:20). The author’s explicit comparison is that their “last state” becomes worse than their first.
The passage also treats their turning back as more than ignorance. They are said to have “known the way of righteousness” and then to have turned away from a “holy commandment” that was “delivered” to them (2:21). The two proverbs (dog/vomit; washed sow/mire) reinforce the idea of relapse into what is filthy after a genuine escape and some kind of cleansing (2:22).
Where interpretation differs (only where needed)
One main difference is what kind of “knowledge” and “escape” this describes. Some readers think it refers to genuine Christian conversion and participation in the community, so the warning portrays a person truly rescued and then ruined by returning. Others think the “knowledge” can be real exposure to Christian truth and moral reform without deep inner change, so the reversal shows that their attachment was never settled.
A second difference is what “worse” means. Many take it as a final, future outcome before God (a more severe judgment because of greater light). Others emphasize a present, moral and communal collapse (deeper enslavement and shame) while still allowing a future accountability in the background.
Why the disagreement exists
The text uses strong language (“escaped,” “knowledge of…Jesus Christ,” “way of righteousness”), which naturally sounds like genuine Christian experience. At the same time, the chapter’s broader focus is on corrupt teachers and their destructive influence (2:1–19), and the animal proverbs can suggest unchanged nature beneath a temporary wash. Because the passage does not spell out the inner state of the people (only their history and outcome), readers infer different models for how “knowledge” and “escape” relate to lasting allegiance.
What this passage clearly contributes
It clearly teaches that turning back into corrupt patterns after receiving true instruction about Christ is not neutral or minor: it leads to a worse condition than the starting point (2:20–21). It also frames Christian teaching as a “way” and a “holy commandment” that people can genuinely receive and then reject (2:21). Finally, it contributes vivid moral psychology: relapse is not merely drifting but a returning-to-filth dynamic that results in being re-captured and defeated (2:22; cf. 2 Peter 2:19).