Revelation 21:27 Commentary: Only the Written Enter the Holy City

John’s vision of the New Jerusalem draws deeply on Old Testament purity traditions. Numbers 5:3 commands the unclean to be put outside the camp “so that they don’t defile their camp, in the midst of which I dwell.” Leviticus 13:46 isolates the leprous person outside the settlement. The same principle governs access to the temple: Ezekiel 44:9 bars the “foreigner, uncircumcised in heart and uncircumcised in flesh” from the sanctuary. Isaiah 35:8 promises a highway called the Holy Way on which “the unclean shall not pass over,” and Isaiah 52:1 calls Jerusalem to put on beautiful garments because “the uncircumcised and the unclean will no more come into you.”

John reuses this language for the eschatological city. Verse 27’s koinon (“common,” “unclean”) is the same term Peter resists in Acts 10 when the sheet with unclean animals descends, a vision that overturns ritual barriers even as it upholds moral holiness. The word bdelugma (“abomination”) in the Septuagint often refers to idols (Deuteronomy 7:25-26) or detestable practices. Matthew Poole observes that “idols are lies,” explaining why the liar and the abomination-maker are grouped together.

The phrase “Lamb’s book of life” recurs throughout Revelation (3:5, 13:8, 17:8, 20:12, 20:15). It draws on Jewish imagery of a heavenly register (Exodus 32:32, Psalm 69:28, Daniel 12:1). In John’s world, a citizen list determined who belonged to a city; this book defines citizenship in the new creation. The Lamb who was slain (5:6) is the one who writes the names, making entry a matter of his sacrifice rather than human merit.

The most significant textual variant in this verse concerns the first phrase. Several early manuscripts (including Codex Sinaiticus and Codex Alexandrinus) read the adjective koinon (“common,” “unclean”) rather than the participle koinoun (“that which defiles”). Vincent’s Word Studies and the Cambridge Bible support koinon as the preferred reading. The Byzantine majority text follows the participle, which is reflected in the KJV (“anything that defileth”). The meaning is essentially the same: both forms denote that which is ritually or morally impure. A few manuscripts omit “Lamb’s” (tou arniou) in the phrase “book of life of the Lamb,” but the external evidence strongly supports its inclusion. The supplied sources note no other significant variants.

Revelation 21:27 has shaped Christian hope for the life to come. Early patristic writers read it as confirming the purity of the heavenly Jerusalem, free from the defilements of the present age. In the medieval period, the verse was used in preaching on the necessity of holiness and the sacramental cleansing of sin. Reformers like Luther and Calvin appealed to it to distinguish between the church visible (which contains both wheat and tares) and the church triumphant (where only the elect reside). The image of the Lamb’s book of life gave comfort to believers facing persecution, assuring them that their names were secure. In modern hymnody, the verse appears in songs about heaven that long for a place where “nothing defiled shall ever come in.” Across traditions, it has served as both a warning against presumption and a source of hope for those who trust in the Lamb.

Three-point outline

1. The Absolute Exclusion: The double negative (ou mē) forbids anything unclean, anyone practicing abomination, or anyone living a lie from entering the New Jerusalem. This is not a mild caution but an unbreakable boundary.
2. The Positive Condition: The only ones who enter are those “written in the Lamb’s book of life.” The perfect participle (gegrammenoi) indicates a completed action: God has already recorded his people.
3. The Grace Behind the Gate: The same verse that bars sin also opens the door through the Lamb. No one qualifies by their own purity; they are made fit by the Lamb’s blood (Revelation 7:14).

Five-point outline

1. No unclean thing enters. The word koinon means “common, unhallowed” (Vincent). The city reflects God’s absolute holiness.
2. No worshipper of idols enters. Bdelugma is the Septuagint’s term for idolatry; the city leaves no room for rival gods.
3. No liar enters. Pseudos covers falsehood in speech and in living; the city is founded on the truth of God.
4. Only the written enter. The Lamb’s book of life is the sole guest list. It is his book because he purchased the names.
5. Holiness and grace are not opposites. The verse holds together God’s uncompromising purity and his free gift of entry through Christ.

Illustration hooks

• Airport security: No matter how valued a passenger is, no one bypasses the scanner if a prohibited item is found. The city’s single condition is absolute.
• A wedding with a guest list: The host has already chosen whom to invite. Those whose names are on the list enter freely; those not on it cannot force their way in.
• A cleanroom in a factory: Even a speck of dust spoils the product. The New Jerusalem is a “cleanroom” for God’s presence, so nothing defiling can be allowed.

Questions your congregation is asking

• “How can I know if my name is written in the Lamb’s book of life?”
• “If salvation is by grace alone, why does this verse sound like sinners are kept out because of their deeds?”
• “Does this mean people who once believed but later fell into serious sin are excluded?”

This verse confronts us with a tension many Christians feel: the holy city excludes all impurity, yet entry depends on being written in a book, something God does. As you discuss, hold these two truths together. Neither cancels the other.

Discussion questions

1. Read Revelation 21:24-27 aloud. What do the open gates (v.25) and the exclusion of the unclean (v.27) together suggest about the nature of the city?
2. The Greek word koinon means “common” or “unclean.” In what ways do we sometimes treat sin as “common” or ordinary rather than as a barrier to God’s presence?
3. Why do you think “abomination” and “lie” are singled out? How do idolatry and falsehood specifically oppose the character of the New Jerusalem?
4. How does the image of a “book of life” (Exodus 32:32, Revelation 3:5) help us understand assurance of salvation? Does it make you more confident or more uneasy? Share why.
5. This verse follows the statement that the glory and honor of the nations are brought into the city (v.24, 26). How can we bring “glory and honor” to God now while we wait for that day?
6. If the unclean cannot enter, how does anyone enter at all? What role does the Lamb play in making us fit for the city?
7. How might this passage shape the way we view holiness in our daily lives, without falling into the error of thinking we earn our way in?