924. 21:27 But there shall not enter it anything unclean, or that creates an abomination or a lie. This symbolically means that no one is received into the Lord's New Church, which is the New Jerusalem, who adulterates the goods in the Word and falsifies its truths, and who does evils deliberately and so also devises falsities.
Not to enter in means, symbolically, not to be received, as before. Something unclean symbolizes spiritual licentiousness, which is an adulteration of the Word's goodness and a falsification of its truth (nos. 702, 728). For this is absolutely unclean and impure, inasmuch as the Word is absolutely clean and pure, and it is defiled with evils and falsities when it is corrupted. That adultery and licentiousness correspond to an adulteration of the Word's goodness and a falsification of its truth may be seen in nos. 134, 632. To create an abomination or a lie means, symbolically, to do evils and so also to devise falsities. Abominations symbolize evils of every kind, especially those named in the Ten Commandments (no. 891), and a lie symbolizes falsities of every kind, here the falsities that accompany evil, which in themselves are evils. Thus they are falsities used to justify evil, which are the same as evils affirmed.
A lie symbolizes doctrinal falsity because that is what a spiritual lie is. To create a lie, therefore, symbolically means to live in accordance with doctrinal falsities.
(Odkazy: Revelation 21:26)
 That a lie in the Word symbolizes doctrinal falsity may be seen from the following passages:
We have made a covenant with death, and with hell we have produced a vision... ...we have made a lie our refuge, and in falsehood we have hidden ourselves. (Isaiah 28:15)
Everyone deceives his neighbor, and they do not speak the truth; they have taught their tongue to speak a lie. (Jeremiah 9:5)
...this is a rebellious people, lying children..., who will not hear the law of Jehovah. (Isaiah 30:9)
Behold, I am against those who prophesy lying dreams..., and tell them in order to lead My people astray by their lies... (Jeremiah 23:32)
The diviners see a lie, and speak false dreams. (Zechariah 10:2)
(The diviners) see vanity and a lying divination... Therefore..., because you speak vanity and see a lie, behold, for that reason I am against you..., (so that) My hand is against the prophets who speak... a lie. (Ezekiel 13:6-9, cf. 21:29)
Woe to the bloody city! It is all full of lying and robbery. (Nahum 3:1)
In the prophets of Jerusalem I have seen a shocking obstinacy, committing adultery and walking in lies. (Jeremiah 23:14)
From the prophet even to the priest, everyone devises lies. (Jeremiah 8:10)
(In Israel) they have devised lies. (Hosea 7:1)
You are of your father the devil... He was a murderer from the beginning..., because there is no truth in him. When he speaks a lie, he speaks on his own, for he is the speaker of a lie and the father of it. (John 8:44)
Here, too, a lie means falsity.
In Revelation 21:20, 'an unclean thing' signifies spiritual whoring, which is the adulteration of good, and falsification of truth of the Word. This is uncleanness and impurity itself, because the Word is cleanness and purity itself, and it is defiled by evils and falsities when it is perverted.