Is sanctification frequently misunderstood?

Yes. As a matter of fact many do not distinguish between justification and sanctification. So what is sanctification?

The word “sanctify” is found in both the Old and the New Testament (NT). In the NT, the Greek word is hagiazō, which means all of this: to render or acknowledge, or to be venerable or hallow, to separate from profane things and dedicate to God, consecrate things to God, dedicate people to God, to purify, to cleanse externally, to purify by expiation: free from the guilt of sin, to purify internally by renewing of the soul.

When a sinner is justified by God’s grace, he is declared to be righteous, and not guilty, since God imputes the righteousness of Christ to him. And then God expects that person to practically become righteous by “walking in the Spirit” and not fulfilling the desires of the flesh (the sin nature).

Christ said that we are sanctified through the Word of Truth, which is the Word of God (John 17:17) and Ephesians 5:26 and Hebrews 4:12,13 show how this happens: That he might sanctify and cleanse it with the washing of water by the Word… For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart. Neither is there any creature that is not manifest in his sight: but all things are naked and opened unto the eyes of him with whom we have to do.

So when a believer (one had already been justified by grace through faith) reads the Bible, God examines his heart through the Word of God, and convicts the believer of any sinful thoughts and deeds. And as that person turns away from sin and evil, he is sanctified by the purification of his soul and spirit. Thus 1 Thessalonians 5:23 becomes more and more of a reality: And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ.

Paul presents two examples where sanctification applies: For this is the will of God, even your sanctification, that (1) ye should abstain from fornication: That (2) every one of you should know how to possess his vessel [wife] in sanctification and honour (1 Thess 4:3,4)

According to Scripture, sanctification is progressive: According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue: Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust. And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge; And to knowledge temperance; and to temperance patience; and to patience godliness; And to godliness brotherly kindness; and to brotherly kindness charity. For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ. (2 Peter 1:3-8)

At the same time, the very fact that the believer has the indwelling Holy Spirit means that he is also sanctified in God’s eyes because the Holy Spirit is within: But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth…Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied. (2 Thess 2:13; 1 Pet 1:2)

But that is not all. Because we are in Christ Jesus, He Himself is our sanctification: But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:

All of this is meant to be an incentive to practical righteousness and holiness.

Sanctification is indeed misunderstood by many Christians. For many it is a vague belief. For others it is a real heart experience that has set them free from sin to love God with their whole being and their neighbor as themselves.

Heb 5 "For when for the time you ought to be teachers, you have need that one teach again the elementary principals of the oracles of God and are become such as have need of milk rather than strong meat. For anyone who is unskillful in the word of righteousness is a babe and needs milk. Whereas strong meat belongs to them who are of full age, ever those who by reason of use have their senses exercised to discern both good and evil."

I see that you're back, this time with chat-bot responses.
But these techniques are again from the 90s.

Like everything else pertaining to Christianity, all good things are from above.

1 Corinthians 1:30
But it is due to Him that you are in Christ Jesus, who became to us wisdom from God, and righteousness and sanctification, and redemption.

First and foremost, we are sanctified by Jesus Christ, the perfect sanctification.

Of course, we understand that our personal sanctification, is the very will of God for us.

So we practice, implement and follow a sanctified lifestyle.

Always, Christ first.

There is a great need for the truth of sanctification or holiness to be preached from our pulpits. The spiritual life of the average church goer is such that you have to backslide to have fellowship with them. The writer to the Hebrews made it very plain, 'without holiness, no one will see the Lord'. We need more Christians whose hearts have been made pure and whose lives reflect the life of Jesus.