Jehovah's Witnesses feel that “just believing” is too simplistic and that God requires more. Perhaps the greatest resistance for some in accepting Christ’s offer, results from the fear that just believing in Jesus isn’t enough to make a person any better than they were before. This is a critical point. Jehovah’s Witnesses do not understand Sanctification which means to be set apart for the purposes of God. In other words, Jehovah’s Witnesses think that "just believing” in Jesus won’t help you along the road to perfecting holiness. The sanctification doctrine is a key understanding this concern.

Jehovah’s Witnesses are correct if they mean that just believing in the historical existence of Jesus, as a man isn’t enough. However, they are wrong when they use this phrase as an excuse to support a different authority than Jesus, and then use that authority to reject Jesus’ offer of atonement (emblematic bread and wine), and the subsequent in-dwelling of the Holy Spirit whose end result is perfection for the believer through sanctification. It is God’s work, not of men.

For all the good that Witnesses try to live by, it is all by their will power. However, it is their will power that they are so proud that damns them. … “Which things have indeed a shew of wisdom in will worship” – Col. 2: 23

In reality, many end up worshipping their own will. They simply do not believe it possible, nor wish to be like Jesus by virtue of a supernatural means….. being born again with a new nature. Yet, this is the ONLY way outlined in scripture.

This is a problem because God cannot accept anything other than perfect holiness in his family; and He has already rejected man’s efforts at getting there by nailing the Law to the cross, its fulfillment. Since that time, mere human effort and means, regardless how well intentioned, if enacted outside the New Covenant can only elicit God’s wrath, else Christ died for nothing.

Romans 4: 15 Because the law worketh wrath

Yet, at the same time we are told to :

Be ye therefore perfect, even as your Father which is in heaven is perfect - Matt. 5: 48

One author put it this way:

Sanctification can be described as an inward spiritual process whereby God brings about holiness and change in the life of a Christian by means of the Holy Spirit. The effects of living in a fallen world have harmed everybody differently. We all face different issues, struggle with sin, and past hurts of varying degrees, hindering our ability to live the life God desires for us. Once we accept Jesus Christ into our lives, the Holy Spirit enters our life to start a transformation process (progressive sanctification).

He convicts us in areas that need to be changed, helping us to grow in holiness. We begin to view the world, people, and personal difficulties from a more biblical perspective. Our choices begin to be motivated by love and truth and not selfishness and arrogance.

This is the working process of sanctification in the life of every believer. Though the process is personal for each individual, the end goal is to prevent sin and produce spiritual growth. Note that sanctification has nothing to do with living in sinless perfection. We will never be sinless in this life. In fact, the Bible warns against such false teachings in 1 John 1:8: "If we say that we have no sin, we deceive ourselves, and the truth is not in us."

So, no amount of will power can get you there. Your force of will can only elicit God’s wrath. Why? Because, even in a perfect environment, you still have your sin nature inside of you. Your flesh wants to be prideful, take the credit for righteousness, and worse, etc.

By contrast, and quite beyond the will-power of the believer, God foretold and does the following:

I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. - Jer. 31: 31-33

ye are manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart. …Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God. - 2 Cor. 3:3

At the end of God’s work, of which he gets ALL the credit (Phil. 1: 6), the following will be true of whosoever believes and accepts Christ’s offer of an exchanged life:

For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. – Rom. 8:29

It is precisely because you CANNOT get to where God needs you to be on your own that belief is critical to salvation, and not your works. Belief is not a short cut to hypocriticalness or an excuse for duplicity as unsaved critics charge. It is the only thing that will please God, because the only way to get you where you need to be is for God to do it for you… as a gift. If we do not believe or trust God, we will never truly agree to let him do with us as he pleases. It is the same with the surgeon; if we don’t believe in him we will never let him operate on us to cut away the cancer.

However, for the Jehovah’s Witness, he is cut off from the Holy Spirit (the Agent of real change) because he never made the life exchange with Christ in the first place. The unconvicted Witness does not even know that he needs the Surgeon. So, he is left only with his own will power, denials of guilt, and illusions of performance-based righteousness before God

In reality, God does it all for the believer. Faith is not our gift to God. Faith is God’s gift to us. Perfection and holiness is not something we achieve for God, it is something that happens when God lives inside of us. The believer is sculpted and shaped from the inside out, into the image of the Son. Who could ask for something better than this in achieving holiness?

This is another of the reasons why a person must seek to lose his life in order to find it. It is not easy, and it’s against every fiber in your body, but you must surrender the rights to your own life to Jesus. Millions of people will testify to the goodness, peace and holiness that God has delivered in their lives when they have done so.

Righteousness, holiness, and perfection are often minimized in some versions so as not to alarm “religious” people about  the real fruit and end result of living an actual sanctified life.