The Holiness of God and the Call to Be Set Apart

I recently enrolled in Biblical Hebrew school, and it feels like stepping into an entirely new world—one that’s both ancient and alive. I’ve always been fascinated by the original languages of the Bible—Hebrew, Greek, and Aramaic—and how each layer of meaning brings the text to life in ways that translations sometimes can’t fully capture.

Over the years, I’ve spent time diving into different biblical words, exploring what they truly mean within their historical and cultural context. Each word holds depth, poetry, and purpose.

Today, I wanted to share one of those words that has deeply moved me. . X

In Hebrew, there’s a word that appears again and again throughout Scripture — a word that reveals something profound about who God is and who He calls us to be. A word that captures the very heartbeat of God’s nature and our calling as His people.

That word is Kadosh (קָדוֹשׁ).

It means “holy,” “sacred,” or “set apart.”

But it’s far more than just a moral or religious label. Kadosh expresses the very essence of God — His complete purity, perfection, and otherness — and it defines what it means for His people to belong to Him.

The Root Meaning of Kadosh:

The word Kadosh comes from the Hebrew root קדש (Q-D-Sh), which means “to separate” or “to consecrate.” Something that is kadosh is set apart from the ordinary — reserved for a sacred purpose.

In the Old Testament, objects, places, times, and people could all be made holy — not because of their own qualities, but because they were dedicated to God.

The Sabbath was called holy, a day of rest and worship:

“So God blessed the seventh day and made it holy, because on it God rested from all his work that he had done in creation.”

— Genesis 2:3 (ESV)

The Temple and its instruments were holy:

“There I will meet with the people of Israel, and it shall be sanctified by my glory. I will consecrate the tent of meeting and the altar. Aaron also and his sons I will consecrate to serve me as priests.” — Exodus 29:43–44 (ESV)

The priests were called to be holy:

“They shall be holy to their God and not profane the name of their God. For they offer the Lord’s food offerings, the bread of their God; therefore they shall be holy.”

— Leviticus 21:6 (ESV)

But most importantly, Kadosh describes God Himself.

“Kadosh, Kadosh, Kadosh”: The Holiness of God

One of the most powerful moments in Scripture comes from the prophet Isaiah’s vision:

“And one called to another and said:

‘Holy, holy, holy is the Lord of hosts;

the whole earth is full of his glory!’”

— Isaiah 6:3 (ESV)

The repetition — three times holy — is not just poetic; it’s emphatic. It declares that God’s holiness is absolute and complete. He is utterly set apart from sin, imperfection, and creation itself.

In Hebrew thought, holiness is not one of many attributes of God — it’s the foundation of all His attributes. His love is holy. His justice is holy. His mercy is holy.

Old Testament Use of Kadosh:

The word Kadosh appears more than 600 times in the Hebrew Scriptures. Here are a few key passages that capture its meaning:

“Speak to all the congregation of the people of Israel and say to them, You shall be holy, for I the Lord your God am holy.”

— Leviticus 19:2 (ESV)

“Consecrate yourselves, therefore, and be holy, for I am the Lord your God. Keep my statutes and do them; I am the Lord who sanctifies you.”

— Leviticus 20:7–8 (ESV)

“Who is like you, O Lord, among the gods? Who is like you, majestic in holiness, awesome in glorious deeds, doing wonders?”

— Exodus 15:11 (ESV)

“Exalt the Lord our God; worship at his footstool! Holy is he!”

— Psalm 99:5 (ESV)

Each of these reminds Israel — and us — that holiness isn’t just God’s character; it’s His invitation.

Kadosh in the New Testament:

Though the New Testament was written in Greek, the same concept of holiness continues.

The Greek word “hagios” carries the same meaning as kadosh: holy, sacred, set apart.

Jesus embodies perfect holiness — the living presence of Kadosh in human form.

“And the angel answered her, ‘The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore the child to be born will be called holy—the Son of God.’”

— Luke 1:35 (ESV)

Even the forces of darkness recognized Him:

“What have you to do with us, Jesus of Nazareth? Have you come to destroy us? I know who you are—the Holy One of God.”

— Mark 1:24 (ESV)

After His resurrection, this same holiness is passed on to believers — not as a distant ideal, but as a living call.

“But as he who called you is holy, you also be holy in all your conduct, since it is written, ‘You shall be holy, for I am holy.’”

— 1 Peter 1:15–16 (ESV)

Holiness is not perfectionism — it’s belonging.

It’s the visible mark of those who have been set apart by grace to reflect the character of their Creator.

Living Kadosh Today . . .

To be kadosh means living in such a way that your life points to God’s presence — not blending into the world’s patterns but shining with His light.

“Strive for peace with everyone, and for the holiness without which no one will see the Lord.”

— Hebrews 12:14 (ESV)

It’s reflected in:

• The way we love purely and without condition.

• The way we pursue truth and justice.

• The way we honor God in our speech, habits, and relationships.

Holiness isn’t perfection — it’s purpose.

It’s being set apart to reflect the character of the One who is perfectly holy.

The vision of Kadosh doesn’t end in the Old Testament — it echoes through eternity.

In John’s Revelation, heaven still resounds with the same cry Isaiah heard:

“And the four living creatures, each of them with six wings, are full of eyes all around and within, and day and night they never cease to say,

‘Holy, holy, holy, is the Lord God Almighty, who was and is and is to come!’”

— Revelation 4:8 (ESV)

Holiness is the heartbeat of heaven — and the invitation for every believer on earth.

It’s not about separation for its own sake, but about devotion — being set apart for something: to love God wholeheartedly and to make His glory known.

Kadosh reminds us that God’s holiness is not distant, but deeply personal. It shapes how we worship, how we live, and how we love. To walk in holiness is to walk with Him — to be continually transformed into the likeness of the One who is perfectly set apart.

Is there another word that you’d like to see me deep dive into? Feel free to leave it in the comments.