1. Revelation 21:27 (ESV)
  2. Exposition

Why are we told that “nothing unclean will ever enter it”?

Revelation 21:27 (ESV)

27 But nothing unclean will ever enter it, nor anyone who does what is detestable or false, but only those who are written in the Lamb’s book of life.

What is glorious to kings (for example, his harem, his army, his pride, or his self-sufficiency—all acceptable and normal in this life) may be offensive to God—unclean, sinful, offensive. Those bits of kingly glory (as opposed to, say, worthy inventions) will not enter even through open gates, simply because this city is so fully dominated by the God who is fully light. See also Matthew 5:20, Matthew 7:21, and Matthew 18:3.