Revelation 21:22-27

I did not see a temple in the city,
because the Lord God Almighty and the Lamb are its temple.
The city does not need the sun or the moon to shine on it,
for the glory of God gives it light,
and the Lamb is its lamp.
The nations will walk by its light,
and the kings of the earth will bring their splendor into it.
On no day will its gates ever be shut,
for there will be no night there.
The glory and honor of the nations will be brought into it.
Nothing impure will ever enter it,
nor will anyone who does what is shameful or deceitful,
but only those who are written in the Lamb's book of life.
(Revelation 21:22-27)

From AR 876:
"But they that are written in the Lamb's book of life"
signifies that no others will be received into the New Church,
which is the New Jerusalem,
but they who believe in the Lord,
and live according to His commandments in the Word.