A common misinterpretation is that this verse teaches genuine believers can lose their eternal salvation, but the context of false teachers in chapter 2 describes those who superficially knew the truth without true transformation, as evidenced by their return to sin like a dog to its vomit or a sow to mud; another error is assuming it applies only to backsliding Christians rather than emphasizing the hypocrisy and doom of deliberate rejectors of Christ after tasting His knowledge.
II Peter 2:20
King James Version (1769)
20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.
This passage warns that individuals who have come to know Jesus Christ as Lord and Savior, thereby escaping the corrupting influences of the world, face a more severe spiritual condition if they become entangled again in those sins and are overcome by them; their final state becomes worse than their initial one because they have rejected the truth they once embraced, highlighting the greater accountability and danger of apostasy after experiencing enlightenment through Christ.