20 For if, after they have escaped the pollutions of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and overcome, the latter end is worse for them than the beginning. 21 For it would have been better for them not to have known the way of righteousness, than having known it, to turn from the holy commandment delivered to them. 22 But it has happened to them according to the true proverb: “A dog returns to his own vomit,” and, “a sow, having washed, to her wallowing in the mire.” (2 Peter 2:20–22, NKJV)
This passage clearly describes a person escaping the sinful filth of the world through knowing Jesus Christ the Savior, then returning to and being overcome by sin. Yes, it is possible for a Christian to turn away from Christ and by doing so, be lost. This verse does not suggest Christ lacks the power to protect the saved. It shows that a Christian can rebel, return to sin, and consequently be lost. This verse does not teach degrees of punishment. It notes the greater privileges and responsibilities one has to God by having been saved, and then abandoning Jesus by returning to sin. The picture is horrible. The possibility is real. Therefore, strengthen yourself in the Lord and give no place to the devil (Eph. 4:27).