He who is unjust, let him be unjust
He who is unjust is ὁ ἀδικῶν [ho adikōn] : the one acting unjustly, damaging, or doing wrong. One who violates Gods law.1 Let him be unjust is ἀδικησάτω [adikēsatō] : active voice participle: let him do unjustly. He is unjust as shown by his ongoing actions.
he who is filthy, let him be filthy still
He who is filthy is ὁ ῥυπαρὸς [ho hryparos] : morally impure, degenerate, completely bad; . . . a morally filthy person.2 The opposite of καθαρός [katharos] : clean, pure.
After one of Daniels visions, he was told that the words were closed up until the time of the end and that both good and evil would continue: the wicked would not understand the things of God, but the wise would (Dan. Dan. 12:9-10). The same situation is before us in this age. We have much more revelation than Daniel was given, including the entire New Testament and this book of last things. Yet, the wicked continue to ignore the sure prediction of the judgment of God on the horizon. This will culminate in a generation at the time of the Tribulation who are unique in their blasphemy and unrepentant rejection of God. Even though they will know God exists and that He is the source of their judgment (Rev. Rev. 6:15-17+), they will continue in rebellion and refuse every opportunity to repent (Rev. Rev. 9:21+; Rev. 16:8+, Rev. 16:11+). See Beast Worshipers are Unique.
God is saying that men choose to sin because they want to, not because they know no better; and the inference is that even this book, which reveals the ultimate, stark, destiny of sin, will not deter sinners from pursuing their fancy.3In view of this reality, the marching orders of the Church are similar to those of the prophet Ezekiel:
But when I speak with you, I will open your mouth, and you shall say to them, Thus says the Lord GOD. He who hears, let him hear; and he who refuses, let him refuse; for they are a rebellious house. (Eze. Eze. 3:27) [emphasis added]It was not Ezekiels responsibility to make the rebellious turn. His responsibility was to accurately preserve and convey the message of God. Those who would respond did so. Those who would not did not. He did not own the results!
Preaching Revelation draws the line. Its truths will melt the hearts of the repentant and harden the hearts of the unrepentant. Those same truths thus become either an instrument of salvation, or an instrument of damnation (cf. 1Cor. 1Cor. 1:18; 2Cor. 2Cor. 2:15-16).4Paul gave similar instructions to Timothy:
Yes, and all who desire to live godly in Christ Jesus will suffer persecution. But evil men and impostors will grow worse and worse, deceiving and being deceived. But you must continue in the things which you have learned and been assured of, knowing from whom you have learned them. (2Ti. 2Ti. 3:12-14) [emphasis added]he who is righteous, let him be righteous still
he who is holy, let him be holy still
Holy is ὁ ἅγιος [ho hagios] : the holy [one] which is the same root word as saint. They are holy because they are set apart to God and indwelt by the Holy Spirit:
Do you not know that you are the temple of God and that the Spirit of God dwells in you? If anyone defiles the temple of God, God will destroy him. For the temple of God is holy, which temple you are. (1Cor. 1Cor. 3:16-17)
2 Ibid., 343.
3 Monty S. Mills, Revelations: An Exegetical Study of the Revelation to John (Dallas, TX: 3E Ministries, 1987), Rev. 22:11.
4 John MacArthur, Revelation 12-22 : The MacArthur New Testament Commentary (Chicago, IL: Moody Press, 2000), Rev. 22:10.