Peter has it all well covered, one way and another. Sexuality issues are signs that always demonstrate the spiritual state of a person as does the love of money.
v20-22 shows us they are not converted, not born of God as they remained dogs and pigs. That they have spiritual knowledge of God's commands to escape the lusts of this world and yet resist the Holy Spirit also shows they are not of Him. Ancient Israel leaving Egypt also had it's share of these kinds of people, they continually resisted against God.
Acts 7:51 “You stiff-necked and uncircumcised in heart and ears! You always resist the Holy Spirit; as your fathers did, so do you.
'Uncircumcised in heart and ears' means these people are not born again people, they are of the flesh and the evil one, seeking to do as their father the devil, being an adversary of God.
2 Peter 2
New King James Version
Destructive Doctrines
1 But there were also false prophets among the people, even as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Lord who bought them, and bring on themselves swift destruction.
2 And many will follow their destructive ways, because of whom the way of truth will be blasphemed.
3 By covetousness they will exploit you with deceptive words; for a long time their judgment has not been idle, and their destruction does not slumber.
12 But these, like natural brute beasts made to be caught and destroyed, speak evil of the things they do not understand, and will utterly perish in their own corruption, 13 and will receive the wages of unrighteousness, as those who count it pleasure to carouse in the daytime. They are spots and blemishes, carousing in their own deceptions while they feast with you, 14 having eyes full of adultery and that cannot cease from sin, enticing unstable souls. They have a heart trained in covetous practices, and are accursed children. 15 They have forsaken the right way and gone astray, following the way of Balaam the son of Beor, who loved the wages of unrighteousness; 16 but he was rebuked for his iniquity: a dumb donkey speaking with a man’s voice restrained the madness of the prophet.
17 These are wells without water, clouds carried by a tempest, for whom is reserved the blackness of darkness forever.
Deceptions of False Teachers
18 For when they speak great swelling words of emptiness, they allure through the lusts of the flesh, through lewdness, the ones who have actually escaped from those who live in error. 19 While they promise them liberty, they themselves are slaves of corruption; for by whom a person is overcome, by him also he is brought into bondage. 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.”
