What does 2 Peter 2:21 mean?
This verse is part of a larger thought contained in verses 20 through 22. Peter appears to be referring to the ones enticed and deceived by the false teachers in the church. One of the lies of the false teachers was that Christians should freely participate in indulging their sinful desires. Peter describes the effect of this teaching on those who had escaped from the practice of the world and entered into the community of the church.These were people who heard and understood the gospel of Jesus but who had apparently not yet fully trusted in Christ. According to scripture, merely knowing about God is not the same as having a saving faith in Christ (James 2:19). These potential believers were misled by the false teachers and overcome again by their worldly practices.
Peter writes that it would have been better for them never to have heard the gospel, and never to have been told about the way of righteousness, than to know "the holy command"—the gospel, the command to trust in Christ—and to turn away from it.
Why would it be better? Partly because once that message has been heard and rejected, or corrupted, it is very unlikely someone will return again to believe and trust in it. Their attitude towards the gospel is now warped, distorted, and stained. They have added a series of roadblocks and hang-ups to their path towards genuinely accepting Christ. These complications make it all the harder for them to submit to God, and experience eternal salvation with God the Father.
No wonder Peter comes across as so angry in his condemnation of the false teachers. They were effectively leading people away from the hope of Christ and back to their own path of destruction.