The question came up while studying about the false teachers foretold in 2 Peter chapter 2, were the people deceived by these heresies ever really saved or not? I personally, when I read the passage, take it as a warning For us believers not to get sucked into the deception and fall away. The Bible has a great deal to say about the apostasy, or falling away (2 Thes. 2:3), in the last days. I did interject however that there were those who would view the ones so deceived by such teachings as having never been saved. And then, I read a key phrase at the end of chapter 2 in the New Living Translation. Follow my brief skeleton outline.
There will be false teachers among you who cleverly teaching destructive heresies even denying the Lord that bought them (2:1). Many will follow their evil teachings and shameful immorality. Because of them the way of truth will be slandered. In their greed they will think up clever lies to get a hold of your money (2:3). These false teacher are like unthinking animals who follow their natural instincts and scoff at what they do not understand (such as the teachings of Christ’s imminent Return (3:3)).
-They commit adultery with their eyes; their desire for sin is never satisfied.
-They allure UNSTABLE people into sin.
-They wander off the RIGHT ROAD and follow the footsteps of Balaam who loved to earn money by doing what is wrong.
-They boast about themselves.
-With an appeal to twisted sexual desires (sensual passions of the flesh), they allure BACK INTO SIN those who have barely escaped from a lifestyle of deception (from those who live in error according to some translations).
-They promise liberty but they themselves are slaves to sin and corruption. (For your are a slave to whatever controls you. This is the key to discerning these end time heresies, for the gospel of Christ is an overcoming gospel).
When people escape from the wickedness of the world through the knowledge of Jesus (see 2 Peter 1:1-4 about partaking of the divine nature through His great and precious promises) and get tangled up and enslaved in sin AGAIN, they are worse off than before (2:20). It would have been better for them not to have known the WAY OF RIGHTEOUSNESS than to have known it and THEN REJCT THE COMMANDMENT THEY WERE GIVEN TO LIVE A HOLY LIVE (2:21).
In conclusion, while there are always potentially impostures within our congregations that are not truly saved, Peter’s concern here obviously was/is for the believers, and more specifically for those who have “barely escaped” from the entanglements of the world, who could possibly be sucked into these damnable teachings. This becomes obvious when he warns of getting tangled and enslaved again to the ways of world. And finally the clincher is when he says, It would have been better for the person not to have known the way of righteousness than to have known it and “THEN REJECT THE COMMANDMENT THEY WERE GIVEN TO LIVE A HOLY LIFE” (2:21). This was not a special command given just to the people who received Peter’s letter, for we got the same commandment as they did: “For the Scriptures say, “You must be holy because I am holy” (1 Peter 1:16). To me that sums up the real problem with the end time deception, you can get all the benefits of the gospel but reject the command to live holy! This is indeed a damnable heresy and one that Peter predicts will increase more and more before Jesus returns.