2Pe 2:20 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.
2Pe 2:21 For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them.
2Pe 2:22 But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
Like the sow that was clean that went back to the mud,some people that have been saved went back to enjoying sin.
They escaped the pollutions of the world through the knowledge of the Lord and Savior Jesus Christ.
They knew the way of righteousness,but turned from the holy commandment delivered unto them.
Only a person that has been saved can escape the pollutions of the world through the knowledge of Jesus,and can know the way of righteousness,but they turned from it,and that is because they wanted to enjoy sin again,and hold unto it,making their repentance of no effect,and if they sin wilfully after they have received the knowledge of the truth then there is no more sacrifice for sin,for the blood of Jesus will not take away a sin they hold on to.
Rom 11:20 Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear:
Rom 11:21 For if God spared not the natural branches, take heed lest he also spare not thee.
Rom 11:22 Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in his goodness: otherwise thou also shalt be cut off.
Like in the Old Testament if they did not abide by the truth they were cut off,and in the New Testament is they do not abide in the truth by continuing in the goodness of God they shall be cut off.
A person that confesses Christ should understand the truth that God wants them to abstain from sin,for that is what repentance is about,and if a person hates sin,and does not want sin,by the Spirit they can abstain from sin,so there is no excuse.
People that hold unto sin and think they are right with God is not right with God,and they usually err in the love of money and material things for their wants,and also fleshy pleasures.
2Ti 2:19 Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his. And, Let every one that nameth the name of Christ depart from iniquity.
This is the seal that seals the saints that they depart from iniquity.
1Co 15:33 Be not deceived: evil communications corrupt good manners.
1Co 15:34 Awake to righteousness, and sin not; for some have not the knowledge of God: I speak this to your shame.
1Th 5:22 Abstain from all appearance of evil.
Heb 3:12 Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.
Heb 3:13 But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.
Some people depart from God for they go back to enjoying sin,and sin separates us from God,and some did not even start out right in their relationship with Jesus for they repented of their past sins,but held unto sins of the future thinking they were alright with God,and they were covered,which is usually because their denomination does not uphold holiness standards.
So how does we cannot abstain from sin,and sin does not affect our relationship with God apply.
It is people going back to enjoying sin that causes a person to be like a dog going back to their own vomit,and the Bible says that the last generation among many people that they will be pure in their own eyes but not washed away from their filthiness.
Which there are many people that claim Christ that hold unto sin and think they are right with God.