We are called to complete/entire sanctification unto the Lord as these two passages make it clear:

2 Corinthians 7:1

“Therefore, dear friends, since we have such promises, let us cleanse ourselves from every impurity of the flesh and spirit, completing our sanctification in the fear of God.”

1 Thessalonians 5:23

“Now may the God of peace Himself sanctify you completely. And may your spirit, soul, and body be kept sound and blameless for the coming of our Lord Jesus Christ.”

In Numbers chapters 13 and 14 we read of the unwillingness of the Israelites to go in and take the land that God promised them. They saw the walled cities and the giant warriors instead of the God of heaven and earth. They looked back towards Egypt instead of pressing on to the destiny God had for them. They were rebellious and unbelieving and so they failed to receive what God had promised. They were doomed to wander in the wilderness 40 years until their generation died off and the new generation arose.

Many times we think that the Old Testament Promised Land is meant to represent heaven. But we must note that they took the land step by step through warfare. This is not how heaven is going to be, but it is a good picture of a life pursuing holiness. Our Promised Land is to “complete holiness in the fear of God” (2 Cor. 7:1).

Like the Israelites of old we might be intimidated by the thought of such a high and heavenly calling. But, we must not make the mistake they made of fearing the enemies and the strongholds. We must remember the promise of God that He will “sanctify us completely” and keep our “spirit, soul, and body” blameless until the coming of Christ. We should readily acknowledge that apart from Christ we can do nothing, but that with God, all things are possible. We must be strong in the Lord and the power of His might and take the land He has promised us.

What does it mean to be completely sanctified, body, soul and spirit? It means that we love the Lord our God with all our hearts, soul, mind and strength, as well as loving our neighbor as ourselves. God prophesied a promise to His covenant people in Deuteronomy 30:6, “The Lord your God will circumcise your heart and the hearts of your descendants, and you will love Him with all your heart and all your soul so that you will live.” This promise He has fulfilled in the New Covenant by giving us His Holy Spirit to lead us on in the victory of holiness.

In Numbers 13-14 God’s people doubted whether or not it was possible to take the land God had promised. And many in the Church today doubt that we can take the land God has given us. But besides remembering God’s promise to give us the land, we must also remember His command to take it. This is not something God will do without our involvement, just as it is not something we can possibly do without His involvement.

Luke 10:25-28

“Just then an expert in the law stood up to test Him, saying, ‘Teacher, what must I do to inherit eternal life?’ ‘What is written in the law?’ He asked him. ‘How do you read it?’ He answered: ‘Love the Lord your God with all your heart, with all your soul, with all your strength, and with all your mind; and your neighbor as yourself.’ ‘You’ve answered correctly,’ He told him. ‘Do this and you will live.’”

Here Jesus tells the expert in the Law that to inherit eternal life he must fulfill the Law by obeying the heart of the Law. We are told elsewhere that “love fulfills the law” (Rom. 13). And Jesus tells us that many will fail to enter into eternal life because they were “lawless” (Matt. 7). So we must first come to grips with the fact that an obligation is laid on us to obey the command to love God with all of our heart, as well as the command to love our neighbors as ourselves. This obligation, and our awareness that we cannot accomplish it by ourselves should drive us to Jesus, the one who came to set us free from our sins.

The fear of the Lord is the beginning of wisdom (Psalm 111:10). This means that a walk with the Lord begins in understanding that we are obligated to live in the way He commands. This fear should drive us to the throne of grace to receive mercy and help in time of need (Heb. 4). And it is that grace that has promised to set us free from sin by circumcising our hearts and working in us to will and do according to God’s good pleasure (Phil. 3:13). We must start with reverent fear and go forth filled with faith in His empowering grace.

The Israelites were commanded to take the entire Promised Land. But they had to take it one city at a time. They had to take every place on which they set their feet. That means they were to go from complete victory to complete victory. Or as 2 Corinthians 3 puts it, “from glory to glory.” They were to fight victoriously every battle they faced, but they could not expect to win the war overnight.

Paul tells us that we are to “live up to what we have already obtained” (Philippians 3). Jesus told us the Parable of the Talents in which he taught that each person is responsible to use what they have to gain more (Matthew 25:14-30). God does not expect us to use what we don’t have, but what we do have. So when He tells us to love Him with all of our hearts, He is telling us to love Him fully. Of course as we grow in knowledge, experience and grace, we will love Him more, but we must always be loving Him “completely.” Our capacity for loving Him increases as we know Him and His will more fully. And as we grow in capacity He fully expects to grow in love for Him. We are to fight one battle at a time, going from glory to glory. From complete victory to complete victory. From loving God with our whole heart to loving Him with a whole heart that has been enlarged. Walking in complete holiness doesn’t mean we have no room for growth, it just means we are living up to the grace (i.e. talents) and knowledge of His will that we have received.

1 Thessalonians 5:23 gives us hope that as believers in Christ we can be entirely sanctified. And 2 Corinthians 7:1 tells us that we are responsible to be completely sanctified. But we also see from 2 Peter 3:18 that we are to grow in the grace and knowledge of our Lord Jesus Christ. And we learn from 2 Corinthians 3:18 that sanctification is a process by which we go from one degree of glory to another. So how is it that sanctification is a continual process and at the same time entire and complete?

We might illustrate the biblical teaching of entire sanctification with the filling up of a balloon. As air is blown into the balloon the balloon expands. Its capacity to hold air grows. This shows that the filling of the balloon is a process. And yet there is never a time in the process in which the balloon is not entirely filled with air. So it is in Christian sanctification. We are called to grow in the grace and knowledge of the Lord just as the balloon receives more and more air. And yet we are also promised and required to be completely sanctified at all times even as the balloon is always completely filled with air throughout the process.

Paul summarizes biblical entire sanctification in Philippians 3:16 when he states, “In any case, we should live up to whatever truth we have obtained.” This does not imply that we have obtained all knowledge and grace, merely that we are fully walking in the grace and knowledge that we have been given. Nor does it imply that we are to stop seeking more grace and truth, for Paul says a few lines before in Philippians 3:12-15:

“Not that I have already reached the goal or am already fully mature, but I make every effort to take hold of it because I also have been taken hold of by Christ Jesus. Brothers, I do not consider myself to have taken hold of it. But one thing I do: Forgetting what is behind and reaching forward to what is ahead, I pursue as my goal the prize promised by God’s heavenly call in Christ Jesus. Therefore, all who are mature should think this way.”

Maybe the best way to understand what entire sanctification looks like is by looking at its opposite, partial sanctification. As James puts it, “Therefore, to him who knows to do good and does not do it, to him it is sin” (James 4:17). And as he illustrates in James 1:21-25:

“Therefore, ridding yourselves of all moral filth and evil, humbly receive the implanted word, which is able to save you. But be doers of the word and not hearers only, deceiving yourselves. Because if anyone is a hearer of the word and not a doer, he is like a man looking at his own face in a mirror. For he looks at himself, goes away, and immediately forgets what kind of man he was. But the one who looks intently into the perfect law of freedom and perseveres in it, and is not a forgetful hearer but one who does good works — this person will be blessed in what he does.”

Christians are called to act on all that they know of God’s will. This is possible because with such knowledge God also gives the empowering grace we need to fully obey. To fail to act on all the light we have received and work out all of the grace that God has worked in us is to be partially sanctified at best. This is grieving the Holy Spirit by which we were sealed for the day of redemption, and it is a very dangerous practice (Ephesians 4:30). Heberews 3:7-14 warns us that this can have disastrous effects if taken too far:

“Therefore, as the Holy Spirit says: Today, if you hear His voice, do not harden your hearts as in the rebellion, on the day of testing in the wilderness, where your fathers tested Me, tried Me, and saw My works 10 for 40 years. Therefore I was provoked with that generation and said, ‘They always go astray in their hearts, and they have not known My ways.’ So I swore in My anger, ‘They will not enter My rest.’ Watch out, brothers, so that there won’t be in any of you an evil, unbelieving heart that departs from the living God. But encourage each other daily, while it is still called today, so that none of you is hardened by sin’s deception. For we have become companions of the Messiah if we hold firmly until the end the reality that we had at the start.”

Jesus told us that those that endure to the end will be saved (Matthew 24:13). And Paul tells us that we must not grow weary in well doing because we will reap only if we do not give up (Galatians 6:9). Caleb was a man who exemplified this in the Old Testament (Joshua 14:6-15). Though he had grown old, he did not stop pressing on to receive his inheritance. He fought until he had obtained all he was promised. Though there were mighty enemies in the land he refused to be intimidated, but by faith in the Lord he pressed on until he fully possessed his God-given land. In the same way, we must not be intimidated by everything the devil, the world and our flesh throws our way. We must not be satisfied with changing a few bad habits or bad attitudes. We must press on in faith until not only our actions but also our hearts fully glorify the Lord. God did not come just to change our actions but the very thoughts and intents of our hearts. We must not stop until the Spirit of Jesus is manifest from the very core of our being.