Being "holy" is being set apart, the only acceptable way to be set apart, is the way YHWH says. Here are Hebrew and Greek definitions;
“holy” is word #G40 ἅγιος hagios (ha'-ǰiy-os) adj., 1. holy (set apart by Yahweh God unto himself and apart from the world).
“holy” is word #H6918 קָדוֹשׁ qadowsh (kaw-doshe') adj. - קָדֹשׁ qadosh (kaw-doshe'), 1. holy (ceremonially or morally)., 2. (as noun) God., 3. (by eminence) an angel, a saint, a sanctuary., [from H6942], KJV: holy (One), saint. , Root(s): H6942 , See also: G40
Mat 19:16-17, "And see, one came and said to Him, “Good Teacher, what good shall I do to have everlasting life? And He said to him, “Why do you call Me good? No one is good except One – YHWH. But if you wish to enter into life, guard the commands."
Yah is the only perfectly righteous being, yet we are supposed to be like Him, so it is my belief that we should, while on the narrow path seek and become more and more like Him. No matter if we are way off the mark or a little less off the mark we should seek His guidance, direction and strength to be continually more and more like Him.
Mat 5:48, “Beperfect, therefore, as your heavenly Father is perfect.”
“perfect” is word #5046 – teleios: having reached its end, i.e. complete, by ext. perfect, Original Word: τέλειος, α, ον, Part of Speech: Adjective, Transliteration: teleios, Phonetic Spelling: (tel'-i-os), Short Definition: perfect, full-grown, Definition: perfect, (a) complete in all its parts, (b) full grown, of full age, (c) specially of the completeness of Christian character.
Genesis 17:1, “And it came to be when Aḇram was ninety-nine years old, that יהוה appeared to Aḇram and said to him, “I am Strength Almighty – walk before Me and be perfect.”
“perfect” is word #H8549 תָּמִים tamiym (taw-meem') adj., 1. (literally, figuratively or morally) entire., 2. (also, as noun) integrity, truth., [from H8552], KJV: without blemish, complete, full, perfect, sincerely (-ity), sound, without spot, undefiled, upright(-ly), whole. , Root(s): H8552
Psalms 119:1, “Blessed are the perfect in the way, Who walk in the Torah of יהוה!”
1 John 2:5, But whoever guards His Word, truly the love of Yah has been perfected in him. By this we know that we are in Him.”
1 Peter/Kepha 1:13-21, "Therefore, gird up the loins of your mind, be sober, and hope to the end for the undeserved pardon that is to be brought to you at the revelation of Yahshua Messiah. As obedient children, do not conform to the former lusts you had when you lived in ignorance; But as He Who called you is holy, so you also become holy in all your conduct; Because it is written Be holy, for I am holy. And if you call on the Father, Who, without respect of persons judges according to each man's work, conduct yourselves throughout the time of your sojourning here in reverence; Knowing that you were not redeemed with corruptible things, such as silver or gold, from your idolatrous way of life handed down to you by tradition from your forefathers; But with the precious blood of Messiah, as of a lamb without blemish and without spot; Who truly was foreordained before the foundation of the world, but was manifest in these last times for you; Who through Him we do believe in YHWH, Who raised Him up from the dead, and gave Him glory; that your faith and hope might be in YHWH."
“holy” is word #G40 ἅγιος hagios (ha'-ǰiy-os) adj., 1. holy (set apart by Yahweh God unto himself and apart from the world)., 2. (of a person) a holy one., 3. (physically or ceremonially) clean., 4. (morally) blameless., 5. (Note #1) Most explicitly, this is not “a saint” (compare G2413), which denotes a personal, continual lifelong effort to attain such a stature and position of recognized character, along with a formal recognition by the Roman Catholic Church (and variants) and all its stipulations. In fact, Holiness is intrinsic to Yahweh alone, and He works it in those who fear Him and diligently choose to cooperate with Him and His workings. Though one may indeed act upon his command to be holy, he alone can ascribe one as Holy., 6. (Note #2) Most especially, the Redeemed Kinsmen through trust in Jesus Anointed are indeed the holy ones of Yahweh God, with Jesus himself being the Holy One of God (and we ourselves, his redeemed brothers)., [from hagos “an awful thing”], KJV: (most) holy (one, thing), saint , Compare: G53, G2413, G3741 , See also: H6918
1 Peter 1:13-16, “Therefore, having girded up the loins of your mind, being sober, set your expectation perfectly upon the favor that is to be brought to you at the revelation of יהושע Messiah, as obedient children, not conforming yourselves to the former lusts in your ignorance, instead, as the One who called you is set-apart, so you also should become set-apart in all behavior, because it has been written, “Be set-apart, for I am set-apart.”
Leviticus 11:43-47, "You shall not make yourselves abominable with any creature that moves about on the ground. Do not defile yourselves by means of them, nor be made unclean by them. I am YHWH your Heavenly Father. You shall therefore consecrate and sanctify yourselves, and you shall be holy; for I am holy. Neither shall you defile yourselves with any creature that moves about on the ground. I am YHWH, Who brought you up out of the land of Egypt, to be your Heavenly Father. You shall therefore be holy, for I am holy. This is the Law of the animals, and the birds, and every living thing that moves in the waters, and every creature that moves about on the ground. You must distinguish between the unclean and the clean--between the animal that may be eaten, and the animal that may not be eaten."
Leviticus 19:2-4, "Speak to all the congregation of the children of Israyl, and say to them; You shall be holy, for I, YHWH, your Heavenly Father am Holy. Every one of you shall honor his mother and his father, and keep My Sabbaths. I am YHWH your Father. Do not turn to gods nor make for yourselves molten images: I am YHWH your Father."
“holy” is word #H6918 (Mickelson's Enhanced Strong's Dictionaries of the Greek and Hebrew Testaments), H6918 קָדוֹשׁ qadowsh (kaw-doshe') adj. - קָדֹשׁ qadosh (kaw-doshe'), 1. holy (ceremonially or morally)., 2. (as noun) God., 3. (by eminence) an angel, a saint, a sanctuary., [from H6942], KJV: holy (One), saint. , Root(s): H6942 , See also: G40
Isaiah 65:1-6, “I have let Myself be inquired of, not by those who asked; I was found, not by those who sought Me. I said, ‘Here I am, here I am,’ to a nation not calling on My Name. 2, “I have held out My hands all day long to a stubborn people, who walk in a way that is not good, after their own thoughts; 3, the people who provoke Me continually to My face, who slaughter in gardens, and burn incense on slaughter-places of brick; 4, who sit among the burial-sites, and spend the night in secret places, who eat flesh of pigs,a and the broth of unclean meat is in their pots, 5, who say, ‘Keep to yourself, do not come near me, for I am set-apart to you!’ These are smoke in My nostrils, a fire that burns all day. 6, “See, it is written before Me: I am not silent, but shall repay, and I shall repay into their bosom.”
Around AD 600, Pope Boniface IV created All Saints’ Day, and Pope Gregory III later moved this holiday to November 1 in an effort to give a Christian alternative to this pagan celebration. (“Halloween,” Encyclopædia Britannica)
Ezekiel 20:12, "Moreover, I also gave them My Sabbaths, to be a *sign between Me and them, that they might know that I am YHWH Who sanctifies them."
*Sign is Word #H226, Hebrew Dictionary, Strong's Exhaustive Concordance, meaning mark, token, sign, consent, flag, evidence of consent.
This is the same Hebrew word (owth) from Exodus 13:9, this time it is used speaking of a specific Law; the Sabbath and is called the sign/mark/evidence of consent. Also notice how YHWH says, “I am YHWH Who sanctifies them.” If I choose my own way I “sanctify myself” if I choose His way “He sanctifies me.” The following passage shows an example of those who “sanctify themselves” and if we consider the context of time frame, it is end times, shown by the return of YHWH when He will make judgment;
Isaiah 66:15-24, For, behold, יהוה will come with fire, and with his chariots like a whirlwind, to render his anger with fury, and his rebuke with flames of fire. 16, For by fire and by his sword will יהוה plead with all flesh: and the slain of יהוה shall be many. 17, They that sanctify themselves, and purify themselves in the gardens behind one in the center (H310 אַחַר 'achar - H259 אֶחָד 'echad - H8432 תָּוֶךְ tavek, meaning followingbehind one in the centerof a congregation), eating swine's flesh, and the abomination, and the mouse, shall be consumed together, saith יהוה. 18, For I know their works and their thoughts: it shall come, that I will gather all nations and tongues; and they shall come, and see my glory. 19, And I will set a sign among them, and I will send those that escape of them unto the nations, to Tarshish, Pul, and Lud, that draw the bow, to Tubal, and Javan, to the isles afar off, that have not heard my fame, neither have seen my glory; and they shall declare my glory among the Gentiles. 20, And they shall bring all your brethren for an offering unto יהוה out of all nations upon horses, and in chariots, and in litters, and upon mules, and upon swift beasts, to my holy mountain Jerusalem, saith יהוה, as the children of Israel bring an offering in a clean vessel into the house of יהוה. 21, And I will also take of them for priests and for Levites, saith יהוה. 22, For as the new heavens and the new earth, which I will make, shall remain before me, saith יהוה, so shall your seed and your name remain. 23, And it shall come to pass, that from one new moon to another, and from one Sabbath to another, shall all flesh come to worship before me, saith יהוה. 24, And they shall go forth, and look upon the carcasses of the men that have transgressed against me: for their worm shall not die, neither shall their fire be quenched; and they shall be an abhorring unto all flesh."
(H310 אַחַר 'achar - H259 אֶחָד 'echad - H8432 תָּוֶךְ tavek, meaning followingbehind one in the centerof a congregation)
H310 אַחַר 'achar (ach-ar') adv., 1. (properly) the hind part., 2. (generally, as adverb or conjunction) after (in various senses)., [from H309]
H259 אֶחָד 'echad (ech-awd') adj., 1. (properly) united, i.e. one., 2. (as an ordinal) first.
[a numeral from H258]
H8432 תָּוֶךְ tavek (taw'-vek) n-m., 1. a bisection., 2. (by implication) the center.
Psalm 49:13, “This way of theirs is folly to them, Yet their followers are pleased with their words. Selah. Like sheep they shall be laid in She’ol; Death shall shepherd them; And the upright rule over them in the morning; And their form is consumed in She’ol, Far from their dwelling.”
Exodus 31:13-17, “Speak also to the children of Israyl, saying; Surely My Sabbaths you shall keep, for they are a *sign between Me and you throughout your generations, that you may know that I am YHWH Who sanctifies you, and makes you holy"....16-17, "Therefore the children of Israyl shall keep the Sabbath, to observe the Sabbath throughout their generations as a perpetual covenant. It is a sign between Me and the children of Israyl forever, for in six days YHWH made the heavens and the earth, and on the Seventh Day He rested and was refreshed.”