Since I was a small kid, I have come to understand that only holy people will go to heaven. But nowadays, when you say that holiness is necessary in order for a person to go to heaven, you receive opposition from some superlative Christians. They begin to tell you that we are not saved by works, but rather by faith. So, striving for holiness is works, whereas having an anyhow attitude towards sin is faith.

Ep. 2:8 For it is by grace you have been saved, through faith — and this not from yourselves, it is the gift of God —
Ep. 2:9 not by works, so that no-one can boast.
Ep. 2:10 For we are God’s workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do.

Saved from what?

Saved from sin! Sin is the big problem that mankind has. It is the cause of all the problems in the world. It alienates mankind from God (Col. 1:21). Satan destroyed man by bringing sin into man (Jn. 8:44). Every promise of God is conditioned on being righteous.

Salvation from Sin

Ep. 2:8-9 says that we are saved by the grace of God, through faith, and not by works. However, whichever way we are saved, Ep. 2:10 says sons of God are created (born again) in Christ to do good works. Therefore, if we are really saved, we should be doing good works.

Ro. 10:5 Moses describes in this way the righteousness that is by the law: “The man who does these things will live by them.”[Lev. 18:5]
Ro. 10:6 But the righteousness that is by faith says: “Do not say in your heart, `Who will ascend into heaven?’“ [Deut. 30:12] (that is, to bring Christ down)
Ro. 10:7 “or `Who will descend into the deep?’“ [Deut. 30:13] (that is, to bring Christ up from the dead).
Ro. 10:8 But what does it say? “The word is near you; it is in your mouth and in your heart,” [Deut. 30:14] that is, the word of faith we are proclaiming.

Ro. 10:5-8 contrasts between salvation from sin by works and salvation from sin by grace. Whether by grace of by works, salvation from sin follows the principle of control system as found in some fields, such as engineering. The following diagram illustrates a control system.



In the diagram above, the desired behavior is specified by the laws or commandments of God. The actual behavior is your real life in the world. Comparator is your conscience, which compares your real life with the commandments of God. The difference between what the commandments say and how your real life is (error) determines what changes you need to make in your life in order to become righteous. If you seek to make the changes by exercise of your will power, you are trying to achieve salvation by works. But if you depend on the Spirit of God to bring your life up to righteousness, through word of faith, that is salvation by grace of God. The end goal is the same; holiness.

Zec. 4:6 So he said to me, “This is the word of the LORD to Zerubbabel: ‘Not by might nor by power, but by my Spirit,’ says the LORD Almighty.

Righteousness through the Spirit of God

Mt. 19:26 Jesus looked at them and said, “With man this is impossible, but with God all things are possible.”

It is impossible to become holy through the exercise of will power. But if we bring in the Holy Spirit of God, holiness becomes quite easy.

The only problem is that the Holy Spirit only operates in a holy heart. We are not pure in heart and we want to bring in the Holy Spirit to help us purify our hearts. How do we get around this problem? That is where the blood of Jesus Christ comes in and that is the real meaning of the grace or free gift of God. The gift of Jesus Christ to the world, as the Lamb of God who takes away sins, is God’s free gift to mankind.

We can wash our hearts with the blood of Jesus Christ, so that the Holy Spirit could be involved in our lives.

Purification from Sins

Nu. 19:2 “This is a requirement of the law that the LORD has commanded: Tell the Israelites to bring you a red heifer without defect or blemish and that has never been under a yoke.
Nu. 19:3 Give it to Eleazar the priest; it is to be taken outside the camp and slaughtered in his presence.
Nu. 19:4 Then Eleazar the priest is to take some of its blood on his finger and sprinkle it seven times towards the front of the Tent of Meeting.
Nu. 19:5 While he watches, the heifer is to be burned — its hide, flesh, blood and offal.
Nu. 19:6 The priest is to take some cedar wood, hyssop and scarlet wool and throw them onto the burning heifer.

Nu. 19:9 “A man who is clean shall gather up the ashes of the heifer and put them in a ceremonially clean place outside the camp. They shall be kept by the Israelite community for use in the water of cleansing; it is for purification from sin.

Numbers 19 begins with, "This is a requirement of the law that the Lord has commanded." Jesus said that he did not come to abolish the Law, but to fulfill them. Followers of Jesus are meant to also fulfill the Law. However, there is a paradigm shift; everything in the Old Testament is just an earthly representation of spiritual realities. The New Testament follows a direct spiritual view of the spiritual realities.

Jn. 3:12 I have spoken to you of earthly things and you do not believe; how then will you believe if I speak of heavenly things?

Je. 12:5 “If you have raced with men on foot and they have worn you out, how can you compete with horses? If you stumble in safe country, how will you manage in the thickets by the Jordan?

One big problem that Christians have is that Christianity has been disconnected from its root. The Old Testament Israel, especially worship in the old Jerusalem temple, is the root of Christianity (Ro. 11:16-18). Christians attempt to interpret the New Testament teachings without having a good understanding of the earthly version of the spiritual teachings. That is why different churches have formed conflicting doctrines out of the same New Testament teachings.

In the Old Testament, the practice described in Nu. 19:9, which is washing the body with ashes of burnt heifer dissolved in water, actually served the purpose of disinfecting the bodies of the people who gathered in the temple ground from different places, thereby preventing the possibility of epidemic breaking out, it was a type of purification from sin. We then see that purification from sins is carried out by means of the relics of a previous sacrifice dissolved in water, being used to wash away the sins. In the New Testament, there is only one sacrifice; Jesus' sacrifice of atonement for our sins. The relics of Jesus' sacrifice is his blood. In the New Testament, we are dealing with the spiritual blood of Jesus Christ, which we can access by faith through the Holy Spirit. In the New Testament, the spiritual blood of Jesus Christ replaces the ashes of burnt heifer of the Old Testament. The Old Testament’s physical water, in which the ashes of the burnt heifer is dissolved, is replaced with word of faith in the New Testament. We therefore purify our hearts from sins with the blood of Jesus by word of faith through the Holy Spirit.

Ep. 5:26 To make her holy, cleansing her by the washing with water through the word.

Ja. 4:8 Come near to God and he will come near to you. Wash your hands, you sinners, and purify your hearts, you double-minded.

I personally carry out purification from sins, every morning and evening by praying as follows:

“In the mighty name of the Lord Jesus Christ, I sprinkle all my inward and outward parts with the blood of Jesus Christ through the Holy Spirit of God. I wash away from my heart all unrighteousness, every misdeed of the flesh (Ro. 8:13), every act of the sinful nature (Ga. 5:21), by the blood of Jesus Christ through the Holy Spirit.”

As I purify myself by the blood of Jesus using word of faith, I use my imagination to visualize the blood of Jesus (operated by the Holy Spirit) washing my whole being, especially my heart. It has great effect on my life. I also wash members of my family.

Purification from sin does not happen automatically

One very big misconception among Christians is the understanding that once you are baptized into Jesus Christ, the blood of Jesus Christ automatically washes you. This misunderstanding is a result of not knowing the earthly version of cleansing from sin described in the Old Testament. Therefore, all the shouts of “We are not saved by works”, meaning that we don’t need to do anything in order to be saved from sin, are clearly out of ignorance.

Ph. 2:12 Therefore, my dear friends, as you have always obeyed — not only in my presence, but now much more in my absence — continue to work out your salvation with fear and trembling,
Ph. 2:13 for it is God who works in you to will and to act according to his good purpose.

Lk. 13:23 Someone asked him, “Lord, are only a few people going to be saved?” He said to them,
Lk. 13:24 “Make every effort to enter through the narrow door, because many, I tell you, will try to enter and will not be able to.

https://www.youtube.com/watch?v=SOJjlwYG9y4&t=6s